Alkali aluminum complex hydroxide carbonate salt, and a process for producing said salt and its uses

ABSTRACT

According to this invention, an amorphous or pseudo-boehmite-type hydrated alumina gel and an alkali metal carbonate or bicarbonate as starting materials are reacted in an aqueous medium to give a method of producing a process for producing an alkali aluminum complex hydroxide carbonate salt which is industrially low-cost and has high productivity. Furthermore, by using a gibbsite-type hydrated alumina, a lithium aluminum complex hydroxide carbonate salt can be synthesized by a migration method. 
     The lithium aluminum complex hydroxide carbonate salt and the sodium aluminum complex hydroxide carbonate salt obtained by the processes of the present invention have excellent compoundability in pigments and resins. 
     In addition, these complex salts have no foaming hazards at the time of processing the resins and are useful as resin fillers for halogen capturing property, infrared ray absorbing property and excellent transparency. They are especially useful as a stabilizer (halogen capturing agent) for resin films, a warmth-keeping agent (infrared absorbing agent) and an anti-blocking agent.

TECHNICAL FIELD

This invention relates to an alkali aluminum complex hydroxide carbonatesalt having a lithium aluminum complex-type or dawsonite-type crystalstructure, a process for producing said salt, and its uses. Morespecifically, it relates to an alkali aluminum complex hydroxidecarbonate salt which is useful as a heat stabilizer (halogen trapping)for olefin resins containing a chlorine-containing polymer orhalogen-containing catalyst residues, and an anti-blocking agent or awarmth-retaining agent (infrared absorbing agent) of a thermoplasticresin film, and a process for producing said salt.

The present invention also relates to uses of the above-mentioned salt.It especially relates to a resin compounding agent which is easy tocompound in film-forming resins and can form warmth-retaining resinfilms having excellent infrared absorbability and transparency.

BACKGROUND TECHNOLOGY

Chlorine-containing polymers such as a vinyl chloride polymer are liableto be colored by heat-decomposition reaction such asde-hydrochlorination or to be reduced in mechanical properties in heatmolding processing or subsequent heat histories. To prevent the abovetroubles, it is generally required to compound stabilizers.

Olefin-type resins produced by using Ziegler-type catalysts containhalogen-containing catalyst residues. These residues generate hydrogenchloride at the time of heating and molding to cause rust in the moldingmachines or generate deterioration in the resins, for example,yellowing. To prevent this deterioration, stabilizers which traphydrogen chloride were compounded widely.

The use of hydrotalcite as such a stabilizer has been knonwn from old.For example, Japanese Laid-Open Patent Publication No. 80445/1980describes that hydrotalcite is used as a stabilizer forhalogen-containing resins. Further, Japanese Patent Publication No.36012/1983 shows that a β-diketone compound and a hydrotalcite offormula (1)

    Mg.sub.1-x.Al.sub.x (OH).sub.2.A.sub.x/2.mH.sub.2 O        (1)

wherein x denotes a number of 0<≦<0.5, A represents CO₃ ²⁻ or SO₄ ²⁻,and m represents a positive number are compounded in ahalogen-containing resin.

Furthermore, Japanese Patent Publication No. 30737/1984 discloses thatat least 0.01% by weight of a complex compound represented by generalformula (2)

    M.sub.x Al.sub.y (OH).sub.2x+3y-2z (A).sub.z.aH.sub.2 O    (2)

wherein M represents Mg, Ca or Zn, A represents CO₃ or HPO₄, x, y and zrepresent a positive number, and a is zero or a positive number,

is compounded in a polyolefin containing halogen-containing catalystresidues produced by using a Ziegler-type catalyst.

Hydrotalcites are non-toxic complex hydroxide and carbonate salts ofmagnesium and aluminum, have excellent heat stability, and aretransparent when compounded in a polymer.

These hydrotalcites ideally have a chemical composition expressed byformula (3)

    Mg.sub.6 Al.sub.2 (OH).sub.16.CO.sub.3.mH.sub.2 O          (3)

wherein m is 0 or a positive number.

However, Mg and Al, within a very broad range, form a solid solution asshown by formula (1) or (2), and there is a problem in that it isdifficult to form a composition having a strictly constant composition.

A report of C. J. Serna et al. entitled "Crystal-Chemical Study ofLayered [Al₂ Li(OH)₆ ]⁺ X⁻.nH₂ O" (Clays and Clay Minerals, Vol. 25,page 384 (1977)) describes that a lithium aluminum complex hydroxidesalt is synthesized by adding a benzene solution of aluminumtri(sec-butoxide) (ASB) as liquid drops to an excessive aqueous solutionof lithium carbonate, hydrolyzing ASB, washing the resulting gel, andthereafter, hydrothermally treating the washed gel for several days at130° C.

A report of I. Sissoko et al. entitled "Anion Intercalation and Exchangein Al(OH)₃ -Derived Compounds" (Journal of Solid State Chemistry, Vol.25, pages 283-288 (1985) describes that a lithium aluminum complexhydroxide salt is produced by adding AlCl₃ as liquid drops to an aqueoussolution containing LiOH and Na₂ CO₃ (or Na₂ SO₄), changing the pH from13 in the early period to 10.2 in the last stage to form a gel-likeprecipitate, and aging the precipitate with stirring (see ComparativeExample 6 and FIG. 6 to be given below).

U.S. Pat. Nos. 4,116,856 and 4,221,767 disclose that crystals oflithium. aluminum complex hydroxide salt are produced by reactingamorphous Al(OH)₃ or crystalline hydrated alumina (such asnordstrandite, bayerite, gibbsite) with LiOH, and then reacting themixture with LiX (wherein X represents a halide). However, the resultingcrystals are sol-like and are very difficult to filter.

U.S. Pat. Nos. 5,356,567, 5,360,859, and 5,419,883 describe a lithiumaluminum complex hydroxide salt (to be referred to as LAHS) of generalformula (4)

    [Al.sub.2 Li(OH).sub.6 ].sub.n X.mH.sub.2 O                (4)

wherein X is an inorganic or organic anion, n is the valence of theanion, and m is a number of 3 or below,

having at least 10, especially at least 20 of an orientation degree (OD)defined by formula (5)

    OD=I(002)/I(110)                                           (5)

wherein I(002) represents a relative intensity of an X-ray diffraction

(Cu-Kα) peak appearing in the index of a plane (002) at a spacing (d) of7.67 to 7.84 Å, and I(110) represents a relative intensity of an X-raydiffraction (Cu-Kα) peak appearing in the index of a plane (110) at aspacing (d) of 4.41 to 4.45 Å.

For example, as typical examples of LAHS, lithium carbonate and aluminumchloride are reacted in an aqueous solution in the presence of sodiumcarbonate and sodium hydroxide, a higher fatty acid or a surface-activeagent is added as an orientation enhancer to the reaction mixture, andthe mixture is treated at a temperature of 60 to 100° C. so that thedegree of orientation becomes at least 10.

As another type of the alkali aluminum complex hydroxide carbonate salt,sodium aluminum complex hydroxide carbonate salts having adawsonite-type crystal structure are known. Methods of synthesizingthese salts are known from Japanese Patent Publication No. 38318/1972,Japanese Patent Publication No. 17718/1979, Japanese Laid-Open PatentPublication No. 22628/1981, Japanese Patent Publication No. 44604/1982,Japanese Laid-Open Patent Publication No. 61625/1982, Japanese Laid-OpenPatent Publication No. 83933/1984, Japanese Laid-Open Patent PublicationNo. 100017/1988, Japanese Patent Publication No. 24731/1989, JapanesePatent Publication No. 58205/1990 and Japanese Laid-Open PatentPublication No. 271116/1991.

As a synthesizing method of the above product, Japanese PatentPublication 38313/1972 discloses a method of producing dawsonite whichcomprises reacting an aluminum salt and sodium carbonate using at least2 moles of CO₂ per mole of Al₂ O₃, and maintaining the pH of thereaction mixture at 7.2 to 10.5.

However, LAHS synthesized by these known methods is in the form ofgel-like particles, and the growth of crystals is still insufficient.The shape and size of these particles are non-uniform, and are stillunsatisfactory as a compounding agent for resins.

Furthermore, dawsonite is fibrous. Many of these fibers are entangled inthe form of fibrous ball. Accordingly, they are still unsatisfactory inuse as a compounding agent for resins.

Furthermore, synthesizing methods for known alkali aluminum complexhydroxide carbonate salts must treat the starting materials and theproducts as a dilute solution or slurry. Otherwise, the liquids have ahigh viscosity, and their stirring is difficult. Thus, the productivityis low, and the cost of production is high. Another problem is that theresulting alkali aluminum complex hydroxide carbonate salts are verydifficult to filter, and a long period of time is required for thefiltration process.

The fate of the alkali aluminum complex hydroxide carbonate salts isthat it is essential to use alkali metal compounds as a startingmaterial. These resulting products contain free alkali metal componentsas impurities in addition to alkali metal components charged into thecompounds. These free alkali metal components lead to the defect thatthey may color the resins in which these alkali metal components arecompounded.

DISCLOSURE OF THE INVENTION

The present inventors have found an unexpected fact that when amorphousor pseudo-boehmite type hydrated alumina gel is used as an aluminumcomponent and the concentration of Al₂ O₃ is maintained at a high levelin the reaction system, an alkali aluminum complex hydroxide carbonatesalt can be synthesized within a relatively short period of reactiontime and the filtration of the product can be very easily carried out.

Furthermore, the present inventors have found that when gibbsite-typealuminum hydroxide is utilized as a mother or template for LAHS andlithium is migrated to the vacancy of gibbsite, a highly crystalline anddense LAHS can be obtained.

An object of this invention is to provide a method for producing analkali aluminum complex hydroxide carbonate salt in which the reactioncan be carried out by maintaining the concentration of the startingmaterial in the reaction mixture at a high level, the synthesis can beperformed within a very short period of reaction time, and furthermore,the filtration and washing with water of the reaction product areextremely easy.

Another object of this invention is to provide an alkali aluminumcomplex hydroxide carbonate salt and its uses in which the dispersion ina resin can be easily carried out and the deterioration tendency of theresin is markedly reduced.

Yet another object of this invention is to provide a lithium aluminumcomplex hydroxide carbonate salt in which the crystals are grown to ahigh level, have a large bulk density, and have excellentpigmentability.

A further object of this invention is to provide a process for producingLAHS having excellent producibility and cost, which can be carried outwithin a very short period of reaction time while maintaining theconcentration of the starting material in the reaction system at a highlevel.

An additional object of this invention is to provide a resin compoundingagent composed of the lithium aluminum complex hydroxide carbonate salt.

According to this invention, there is provided a process for producingan alkali aluminum complex hydroxide carbonate salt (to be referred tosimply as a hydrated alumina gel method) which comprises reactingamorphous or pseudo-boehmite type hydrated alumina gel with an alkalimetal carbonate or bicarbonate in an aqueous medium while maintainingthe concentration of alumina (Al₂ O₃) at 1 to 5% by weight under suchconditions in which the pH at the time of termination of the reaction is7 to 11.

According to this invention, there is also provided a process forproducing a lithium aluminum complex hydroxide carbonate salt (to bereferred to simply as a migration method) which comprises reacting fineparticles of gibbsite-type aluminum hydroxide with a combination of alithium compound and a carbonate salt capable of forming a lithium saltof carbonic acid or a carbonic acid ion and a lithium ion in thepresence of water.

According to this invention, there is further provided a lithiumaluminum complex hydroxide carbonate salt (to be referred to as LAHCS)which has a composition represented by formula (6a),

    mAl.sub.2 O.sub.3.nM.sub.2 O.X.kH.sub.2 O                  (6a)

wherein X represents an inorganic anion composed mainly of a carbonicacid radical, M represents an alkali metal composed mainly of lithium, mis a number of 1.5 to 2.5, n is a number of 0.1 to 1, and k is a numberof 0 to 10,

and which has an X-ray diffraction pattern shown below

    ______________________________________                                        Spacing d (A)                                                                 Index of a plane                                                                             Peak intensity                                                 ______________________________________                                        7.50 to 7.64   Large                                                          (002)                                                                         4.30 to 4.44   Small                                                          (110)                                                                         3.70 to 3.84   Large                                                          (004)                                                                         2.45 to 2.58   Medium                                                         (006)                                                                         2.20 to 2.30   Small                                                          (016)                                                                         1.85 to 2.08   Small                                                          (017)                                                                         1.40 to 1.52   Small                                                          (330)                                                                         1.38 to 1.48   Small                                                          (600)                                                                         ______________________________________                                    

the lamination asymmetry index (Is) being

    defined by Is=tan θ.sub.2 /tan θ.sub.1         (7)

(wherein θ₁ represents an angle formed between a peak perpendicular anda peak tangent on the narrow angle side at an X-ray diffraction peak ofa fixed spacing, and θ₂ represents an angle formed between the peakperpendicular and a peak tangent on the wide angle side at the peak),

and IS being 1.0 or below at the peak of an index of a plane (016) and1.0 or below at the peak of an index of a plane (017), and preferablythe LAHCS has a specific resistance of at least 8000 Ω·cm when it isformed as an aqueous slurry having a concentration of 5% by weight.

According to this invention, there is provided a sodium aluminum complexhydroxide carbonate salt (to be referred to as NAHCS) which has acomposition of the following formula (6b)

    mAl.sub.2 O.sub.3.nM.sub.2 O.X.kH.sub.2 O                  (6b)

wherein X represents an inorganic anion composed mainly of a carbonicacid radical, M represents an alkali metal composed mainly of sodium, mrepresents a number of 0.5 to 1.5, n represents a number of 0.1 to 1 andk represents a number of 0 to 3,

said sodium aluminum complex hydroxide carbonate salt has adawsonite-type crystalline structure, the half width of the peak of anindex of a plane in a Cu-α X-ray diffraction pattern is at least 0.4degree, and the sodium aluminum complex hydroxide carbonate salt, whenformed into an aqueous slurry having a concentration of 5% by weight,has a specific resistance of 8000 Ω·cm or below.

According to this invention, there is also provided a resin compoundingagent, especially a warmth-retaining agent or a halogen scavenger forresins, said resin compounding agent being composed of the lithiumaluminum complex hydroxide carbonate salt or the dawsonite-type sodiumaluminum complex hydroxide carbonate salt.

According to this invention, there are also provided a warmth-retainingresin composition comprising a thermoplastic resin and 0.1 to 50 partsby weight, especially 1 to 20 parts by weight, per 100 parts by weightof the thermoplastic resin, of an alkali aluminum complex hydroxidecarbonate salt having a dawsonite-type crystalline structure, and anagricultural film composed of said resin composition.

SIMPLE DESCRIPTION OF DRAWINGS

FIG. 1 is an X-ray diffraction pattern of hydrated alumina used as astarting material, wherein (A) is an X-ray diffraction pattern of agibbsite-type of hydrated alumina, (B) is an X-ray diffraction patternof pseudo-boehmite-type hydrated, alumina, and (C) is an X-raydiffraction pattern of amorphous hydrated alumina gel.

FIG. 2 is an X-ray diffraction pattern of LAHCS in accorance with amigration method of the present invention.

FIG. 3 is a model diagram of a migration reaction.

FIG. 4 is an X-ray diffraction pattern of a lithium aluminum complexhydroxide carbonate salt (LAHCS) according to the production method ofthis invention.

FIG. 5 is an X-ray diffraction pattern of a lithium aluminum complexhydroxide carbonate salt according to a conventional co-precipitatingmethod.

FIG. 6 is a scanning-type electron microscopic photograph showing aparticle structure of a lithium aluminum complex hydroxide saltaccording to the production method described in the literature referenceof I. Sissoko et al. in Comparative Example 6.

FIG. 7 shows enlarged views of peaks of indices of a plane (016) and(017) indicating an X-ray diffrraction pattern of a lithium aluminumcomplex hydroxide carbonate salt, which also show a method of seeking alaminated asymmetry index.

FIG. 8 is a scanning-type electron microscopic photograph showing aparticle structure of LAHCS at a magnification of 5000 times inaccordance with a migration method of the present invention.

FIG. 9 is an electron microscopic photograph showing a particlestructure of LAHCS at a magnification of 10000 times in accordance witha migration method of the present invention.

FIG. 10 is an infrared absorption spectrum chart of LAHCS in accordancewith a migration method of the present invention.

FIG. 11 is a scanning-type electron microscopic photograph showing aparticle structure of a lithium aluminum complex hydroxide carbonatesalt (LAHCS) according to Example 5 of the present invention.

FIG. 12 is an infrared absorption spectrum chart showing dawsonite usedin Example 11 of the present invention.

FIG. 13 is an infrared absorption spectrum chart showing hydrotalciteobtained in Comparative Example 8.

FIG. 14 is a differential thermal analysis curve of dawsonite used inExample 11 of the present invention.

FIG. 15 is an X-ray diffraction pattern of a sodium aluminum complexhydroxide carbonate salt (dawsonite) in accordance with a conventionalmethod (Example 11).

FIG. 16 is an X-ray diffraction pattern of a dawsonite-type sodiumaluminum complex hydroxide carbonate salt (NAHCS) in accordance withExample 7.

FIG. 17 is a scanning-type electron microscopic photograph showing aparticle structure of a sodium aluminum complex hydroxide carbonate salt(dawsonite) in accordance with a conventional method (Example 11).

FIG. 18 is a scanning-type electron microscopic photograph showing aparticle structure of a dawsonite-type sodium aluminum complex hydroxidecarbonate salt (NAHCS) according to Example 7 of this invention.

FIG. 19 is an infrared absorption spectrum chart of a dawsonite-typesodium aluminum complex hydroxide carbonate salt (NAHCS) in accordancewith Example 7 of this invention.

BEST FORM FOR PRACTISING THE PRESENT INVENTION A Process for Producingan Alkali Aluminum Complex Hydroxide Carbonate Salt (1) A HydratedAlumina Gel Method

In the production method of this invention, the first characteristic isthat amorphous or pseudo-boehmite type hydrated alumina gel is used asan aluminum component. By using the hydrated alumina gel, it is possibleto maintain the concentration of Al₂ O₃ in the reaction system at ahigher level than when a water-soluble aluminum chloride is used, andthe reaction can be carried out within a shorter period of time.

Hydrated alumina, generally called aluminum hydroxide, includes variousknown types such as gibbsite, boehmite and diaspore. In accordance withthis synthesizing method, amorphous or pseudo-boehmite is selected, andused. Attached drawings, FIG. 1, (B) shows an X-ray diffraction patternof pseudo-boehmite-type hydrated alumina gel, and (C) shows an X-raydiffraction pattern of amorphous hydrated alumina gel.

In this synthesizing method of this invention, this amorphous orpseudo-boehmite type hydrated alumina gel is reacted with an alkalimetal carbonate salt or bicarbonate salt in an aqueous medium, and thesecond characteristic is that the concentration of alumina (Al₂ O₃)becomes 1 to 5% by weight, and the pH at the end of termination of thereaction is maintained at 7 to 11. This increases the filtrability andwashability with water of the resulting alkali aluminum complexhydroxide carbonate salt markedly. For example, as compared with thealkali aluminum complex hydroxide carbonate salt resulting fromwater-soluble aluminum salt as a starting material; in accordance withthe synthesizing method of this invention, the filtration time can beshortened to about 1/10, and the required amount of water to be used canbe saved to about 1/2.

The fact that an increase of the concentration of alumina results inincreasing the filtrability of the resulting alkali aluminum complexhydroxide carbonate salt has been found as a phenomenon. Although thereason for increased filtrability of the resulting carbonate salt isnever bound to the above fact, it is presumed that in the reactionsystem of the present invention, primary particles formed by thereaction of the above carbonate salt or bicarbonate salt grow tosecondary particles having relatively large sizes, and this growthcontributes to increased filtrability and washability. This agrees withthe fact that stirring in the reaction system is easy despite a highsolids concentration in the system.

The hydrated alumina used in this invention has an amorphous orpseudo-boehmite structure. This is considered to be closely related to ahigh reactivity. The gel is an assemblage of colloidal particles upon aloss of independency. Since these colloidal particles are in anamorphous state or in a condition near it, and since the gel is hydratedtogether with a sol which is independent as colloidal particles, it isbelived that the hydrated alumina has very high reactivity. In addition,since the gel is an assembly of colloidal particles, even when theconcentration of alumina in the reaction system is increased, it isconsidered that the viscosity in the liquid is lowered, and the stirringcan be easily carried out advantageously.

The amorphous or pseudo-boehmite type hydrated alumina gel may beobtained by using aluminum chloride and aluminum nitrate as the aluminumsalt. Preferably, aluminum sulfate or basic aluminum sulfate is reactedwith sodium carbonate and/or sodium bicarbonate, especially sodiumbicarbonate, for neutralization. The hydrated alumina so obtained hasexcellent actions mentioned above, and is especially excellent as astarting material of the alkali aluminum complex hydroxide carbonatesalt of the present invention. Generally, by maintaining the pH duringneutralization at 4 to 8, the amorphous or pseudo-boehamite typehydrated alumina gel is precipitated. It is filtered and washed withwater and used as the starting material in this invention. In view ofthe filtrability and washability with water of the finally neutralizedproduct, it is preferred that the reaction is carried out under heatingat a temperature of 40 to 95° C., further in view of the heatdecomposability of sodium carbonate and/or sodium bicarbonate, thereaction is carried out under heating at a temperature of 50 to 90° C.When basic aluminum sulfate is used as the starting material, the amountof sodium carbonate used for neutralization is small, and the process isadvantageous beccause the presence of sodium sulfate is few. This basicsodium sulfate is obtained by adding calcium hydroxide to eliminate apart of the sulfuric acid radical from aluminum sulfate so thatwater-solubility may not be lost. The number of moles of the sulfuricacid radical is within a range of 0.9 to 3 per Al₂ atom.

It is important in this invention that the reaction is carried out sothat the concentration of alumina (Al₂ O₃) becomes 1 to 5% by weight,especially 1.5 to 4% by weight. When the concentration of alumina islower than the above range, it tends to become difficult to obtain aproduct having good filtrability and washability with water. On theother hand, when the concentration exceeds the above range, theviscosity of the reaction system becomes too high and it is difficult tostirr the reaction system whereby the uniformity of the reaction cannotbe obtained.

It is also important that the reaction is carried out under such acondition that the pH at a time of termination of the reaction ismaintained at 7 to 11, especially 8.5 to 10.5. If the pH is higher thanthe above range, the hydrated alumina gel is crystallized or thereactability with the alkali metal carbonate salt or bicarbonate salt islowered. On the other hand, if the pH is lower than the above range, acarbonic acid ion can no longer exist stably in the system, and thereactability tends to be lowered.

The mole ratio of the amorphous or psedo-boehmite type hydrated aluminagel to the alkali metal carbonate salt or bicarbonate salt [CO₃ /Al] issuitably at least 0.25, especially 0.25 to 4.

The suitable reaction temperature is in a range of 40 to 95° C., and thesufficient reaction time is about 1 to 12 hours. The addition sequenceof the starting compounds is not particularly limited. The hydratedalumina gel and the carbonate salt or bicarbonate salt may besimultaneously poured to the reaction system, or the carbonate salt orbicarbonate salt may be added to the hydrated alumina gel, or they maybe poured in a reverse sequence.

The resulting alkali aluminum complex hydroxide carbonate salt isseparated from the reaction mother liquor by filtration, washed withwater and dried to form a product. The resulting alkali aluminum complexhydroxide carbonate salt may be surface-treated with surface treatingagents to be mentioned later in the reaction mother liquor.

The chacteristic of this invention is that when the alkali metal salt tobe reacted with the amorphous or pseudo-boehmite type hydrated aluminais a conbination of sodium carbonate and lithium carbonate, an alkalialuminum complex hydroxide carbonate salt composed of a mixed crystal ofLAHCS and dawsonite is obtained.

The alkali aluminum complex hydroxide carbonate salt crystal as formedcontains about 0.5 to 3 moles (m) of water although varying dependingupon the synthesis conditions. When this crystal is heated and dried ata temperature of 300° C. or below, the above crystal can be dehydratedpartly or completely.

(2) Migration Method

According to the migration method of this invention, when gibbsite-typealuminum hydroxide as fine particles are reacted with a combination of alithium compound and a carbonate salt capable of forming a lithium saltof carbonic acid or lithium carbonate in the presence of water, alithium aluminum complex hydroxide carbonate salt will be produced.

FIG. 1, (A) shows an X-ray diffraction pattern of gibbsite-type hydratedalumina gel.

The lithium aluminum complex hydroxide salt (LAHS) results frommigration of a lithium ion in the vacancy of an aluminum hydroxideoctahedron layer having a gibbsite structure and inclusion of an anionto supply its charge. The lithium ion has the smallest ionic radius inthe cation, and in addition, it is a 6-coordinate ion exceptionally as amonovalent ion. Therefore, it comes into the aforesaid vacancy and theLAHS takes the above-mentioned structure.

This reaction has the following characteristic. Namely, since analuminum hydroxide used as a starting material has a gibbsite structure,an aluminum hydroxide is substantially kept insoluble in the reactionsystem. A lithium ion as another starting material migrates into avacancy of an octahedron layer of the aluminum hydroxide. As theresults, the gibbsite structure becomes a mother or template tosynthesize LAHC.

This reaction, the so-called migration reaction is shown in FIG. 3 as amodel diagram. LiOH (the upper surface is shown by a hatch) migrates tothe vacancy (vacancy . . . shown by white) of an Al(OH)₃ octahedron(shown by a shadow) of gibbsite and an interlayer carbonic acid anion(shown by a ball and stick) comes into the layers, where Li₂ Al₄ (OH)₁₂CO₃.3H₂ O is synthesized.

It is essential that the aluminum hydroxide used as a starting materialof this invention should have a gibbsite-type crystal structure. It isimportant that the aluminum hydroxide is a fine particulate form withrespect to a migration reaction. Preferably, this compound has anaverage particle diameter of generally 0.5 to 5 μm, especially 0.5 to 3μm, and also has 2% by weight or below, especially 0% by weight orbelow, of coarse particles having a particle diameter of at least 20 μm.When the average particle diameter is larger than the above range, orthe content of coarse particles is larger than the above range, theformation of LAHC by migration tends to be imperfect. On the other hand,if the particle diameter becomes too fine, the particles tend to becomeamorphous, and are unsuitable for the migration reaction.

FIG. 2 shows an X-ray diffraction pattern of one example of theresulting lithium aluminum complex hydroxide carbonate salt. Acomparison of FIG. 1,(A) (gibbsite) with FIG. 2 (LAHC) clearly showsthat in LAHC, the peak of an index of a plane (002) migrates to a lowerangle side and the spacing increases, namely the carbonic acid radicalis introduced between basic layers.

In carrying out the reaction, temperatures required for migrating of alithium ion to the cacancy of the aluminum hydroxide octahedron layerare necessary. Reaction temperatures of generally at least 70° C.,especially 80 to 130° C., are desirable. On the other hand, the pH ofthe reaction system should not substantially dissolve the gibbsite-typealuminum hydroxide. Suitably, it is from 9 to 13.

In the method of this invention, the synthesis can be performed whilethe concentration of the solid content in the reaction system ismaintained at a high concentration of 10 to 20% by weight, and thisbrings about much advantage.

The gibbsite-type aluminum hydroxide as fine particles used as thestarting material in this invention are easily available as a commercialsynthetic product, for example hizilite, manufactured by Showa DenkoCo., Ltd.

The gibbsite-type aluminum hydroxide desirably possesses the aforesaidparticle characteristics, but even if it has particle characteristicsoutside the above range, its particle characteristics are adjusted tothe above range by wet pulverization and can be used in the reaction ofthis invention.

Other starting materials may include a combination of a lithium compoundand a carbonic acid salt capable of forming a lithium salt of carbonicacid or lithium carbonate.

Examples of the lithium salt of carbonic acid include lithium carbonate,lithium bicarbonate, and a mixture of these compounds. Lithium carbonateis best suited as the starting material because it does not give saltsof lithium carbonate as by-products.

Instead of using a lithium salt of carbonic acid, a combination of alithium compound capable of forming a carbonic acid ion and a lithiumion and a carbonic acid salt may be used. As the lithium compound,water-soluble lithium compounds such as lithium hydroxide, lithiumchloride and lithium nitrate may be used. As the carbonic acid salt,sodium carbonate, potassium carbonate and sodium bicarbonate may beused.

In the method of this invention, the lithium-type starting material maybe used in an equivalent weight or more based on the gibbsite-typealuminum hydroxide. Since generally the efficiency of the reaction isgood, it may be used in an equivalent weight or a slightly excessiveamount to the equivalent weight.

In performing the reaction, the gibbsite-type aluminum hydroxide and thelithium-type starting material in the form of a solution may becontacted in the presence of water. At this time, there is no particularrestriction in the order of adding the starting material. The lithiumstarting material in the form of a solution or a solid may be added toan aqueous suspension of aluminum hydroxide. Or conversely, aluminumhydroxide may be added to a solution of the lithium starting material.Or aluminum hydroxide and the lithium starting material may besimultaneously poured in an aqueous medium.

The reaction can be carried out in an aqueous medium whose solidsconcentration is relatively thin. One advantage of the migration methodof this invention is that the synthesis can be performed in a highconcentration such as a solids concentration of, for example, 10 to 20%by weight. LAHC can be synthesized with good efficiency by using areaction vessel of a relatively small volume.

Preferably, the reaction is carreid out with stirring generally at least70° C., especially 80 to 130° C. There is no particular restriction inthe reaction pressure. Generally, the reaction at atmospheric pressureis sufficient. However, when the temperature exceeds 100° C., thereaction may be carried out under an elevated pressure such as anautogenous pressure.

The reaction time varies depending upon the reaction temperature, butgenerally it may be 1 to 10 hours. LAHC can be synthesized within arelatively short period of time.

In the method of this invention, anions other than a carbonic acidradical derived from water-soluble lithium compounds, such as a chlorineion and a nitric acid ion, may co-exist. However, since in this case, acarbonic acid ion is taken preferentially into the lithium aluminumcomplex hydroxide, no particular problem arises. The carbonic acid anionin LAHC desirably occupies at least 50 mole %, especially at least 80mole %, based on the total anions.

After the end of the reaction, the resulting LAHC is subjected to asolid-liquid separating procedure such as filtration, decantation andcentrifugal separation, and as required, washed with water and dried togive a final product. When lithium carbonate is used as the lithiumstarting material, since there is no coexistence of a different kind ofion, the step of washing the product with water can be omitted.

In order to modify the properties of the surface of the resulting LAHC,a higher fatty acid or a surface-active agent is added to the reactionproduct containing LAHC and then LAHC is treated with stirring.

Alkali Aluminum Complex Hydroxide Carbonate Salt

According to this invention, the above process gives an alkali aluminumcomplex hydroxide carbonate salt having a unique crystal structure andextremely little alkali metal components as impurities. It has beenfound that this product has excellent dispersibility in resins, and whenthe above product is compounded in the resins, an effect of a verylittle tendency to deteriorate the resins can be obtained.

(1) Lithium Aluminum Complex Hydroxide Carbonate Salt (LAHCS)

LAHCS is obtained by entering a lithium ion into the vacancy of analuminum hydroxide octahedoral layer having a gibbsite structure, andtaking up an anion to make up for its charge. The lithium ion has thesmallest ionic radius among cations, and since as a monovalent ion, itis exceptionally a 6-coordinate ion, and this monovalent ion enters inthe above vacancy to take up the above structure.

Since LAHCS has a layered structure, exhibits ion exchangeability withrespect to the anion, and shows a structure and characteristics similarto hydrotalcite, it is called a hydrotalcite-like compound or lithiumhydrotalcite. However, LAHCS is quite different from hydrotalcite inchemical commposition and structure because hydrotalcite is obtained byisomorphous-substituting a part of magnesium of the brucite structurewith aluminum.

LAHCS generally has an X-ray diffraction pattern mentioned above. Thelithium aluminum complex hydroxide carbonate salt (LAHCS) according tothis invention, whether by the hydrated alumina gel method or themigration method, is markedly characterized by a lamination asymmetryindex (Is) defined by (1) of not larger than 1.0, especially 0.5 to 1.0,at a peak of an index of a plane (016) and not larger than 1.0,especially 0.5 to 1.0, at a peak of an index of a plane (017).

FIG. 4 is an X-ray diffraction pattern of LAHCS according to the processof this invention in which the alumina starting material is amorphous orpseudo-boehmite-type hydrated alumina. FIG. 5 represents an X-raydiffraction pattern of LAHS according to a conventional co-precipitationmethod. A comparison of FIG. 4 and FIG. 5 shows the fact that with LAHCSaccording to the conventional co-precipitation method, peaks of an indexof a plane (016) and an index of a plane (017) are broad and small andhave a broad tailing on a broad angle side, whereas with LAHCS accordingto the synthetic method of this invention, peaks of an index of a plane(016) and an index of a plane (017) become sharp and high, the aforesaidtailing on a broad angle side disappears and the peaks become a nearlysymmetrical shape with respect to a peak perpendicular.

In FIG. 7 showing a method of seeking the lamination asymmetry index(Is) from the X-ray diffraction patterns of FIGS. 4 and 5, the peaks ofan index of a plane (016) and an index of a plane (017) are magnified,and with respect to these peaks, a narrow angle maximum inclination peaktangent a and a broard angle maximum inclination peak tangent b of thepeaks are drawn, and a perpendicular c is drawn from a point ofintersection between the tangent a and b. Then, an angle θ₁ between thetangent a and the perpendicular c and an angle θ₂ between the tangent band the perpendicular c are sought. The lamination asymmetry index (Is)is sought as a value of Is=tan θ₂ /tan θ₁ . . . (7). This index (Is) is1.0 when the peak is completely symmetrical, and is a larger value whenthe degree of symmetry increases.

With LAHS according to the co-precipitation method, Is values of indexesof planes (016) and (017) are 2.3 and 1.6 respectively, whereas withLAHCS according to the migration method, Is values are 1.0 or less.

This shows that with LAHCS of the present invention, aluminum hydroxideoctahedral basic layers in which a lithium ion is incorporated form alaminated structure in which the basic layers are laminated in thedirection of C axis. By the conventional co-precipitation method, thebasic layers are each shifted in four directions (front, behind, right,left) as seen in the direction of the c axis, and the sizes of the basiclayers are decreased.

On the other hand, in LAHCS according to the hydrated alumina gelmethod, the basic layers are almost over-laped and piled in fourdirections, and the sizes of the basic layers are large andapproximately constant.

The bulk density of LAHCS of this invention is 0.1 to 0.35 g/cm³,especially 0.25 to 0.35 g/cm³, as measured by JIS K6721.

The conventional LAHS shows a BET specific surface area of generally 10to 40 m² /g, whereas LAHCS of the present invention has a BET specificsurface area of 40 to 70 m² /g.

The amount of an oil absorbed is as small as 40 to 70 ml/100 g. Theabove LAHCS has excellent compounding property in resins or paints.

The LAHCS of the present invention has an orientation degree, defined bythe following formula (8)

    OD=I(002)/I(110)                                           (8)

wherein I (002) represents a relative intensity of an X-ray diffraction(Cu-Kα) peak appearing at an index of a plane (002) at a spacing (d) of7.67 to 7.84 Å, and I (110) represents a relative intensity of an X-raydiffraction (Cu-Kα) peak appearing at an index of a plane (110) at aspacing (d) of 4.41 to 4.45 Å,

of smaller than 10 and differs from the orientation degree of at least10 assigned to LAHCS proposed by the present inventors before.

LAHCS of the present invention has a pigment volume concentration of 40to 50%. Since generally PVC of a pigment has a pigment volumeconcentration of 30 to 70%, it can be said that the LAHCS of thisinvention has excellent pigmentability.

The pigment volume concentration is a value defined by the followingformula (9). ##EQU1## Or: The amount of an oil absorbed in the pigment(ml/100 g) Bρ: The density of the resin (g/cm³)

Pρ: The density of the pigment (g/cm³)

That the pigment volume concentration is high shows that the largeamount can be compounded in the coating agent. And also, it shows thatin uses as a resin compounding agent, the filling property andpigmentability are good, and it is advantageous that the compounding inthe resin is easy.

Furthermore, LAHCS of the present invention, when formed as an aqueousslurry having a concentration of 5% by weight, has a specific resistanceof at least 8000 Ω·cm, especially at least 10000 Ω·cm. Thus, thedeterioration of the resin by alkali metal components is markedlysuppressed. This fact will become clear by referring to the followingexample.

FIGS. 8 (a magnification of 5000 times) and 9 (a magnification of 10000times) show electron microscopic photographs of one example of LAHCSaccording to the migration method in accordance with this invention.These photographs show that LAHCS of the migration method of thisinvention has the same hexagonal plate-like particle shape as the LAHCShaving a high orientation degree which the present inventor previouslyproposed, but the thickness of the particles increase as compared withthe gibbsite particles used as the starting material.

Furthermore, these particles have a median diameter (D₅₀), based onvolume standard, of generally 0.2 to 10 μm, especially 0.5 to 6 μm, asmeasured by a laser scattering diffraction method.

FIG. 10 shows an infrared absorption spectrum of the migration method ofLAHCS prepared by the migration method. As is clear from FIG. 10, thisLAHCS has a large infrared absorption spectrum at wave numbers of 547,735,1004, 1375, and 3443 (cm⁻¹), and is useful as an agricultural film,especially a warmth-keeping agent (infrared absorbing agent) of filmsfor greenhouses.

FIG. 11 is a scanning-type electron microscopic photograph showing theparticle structure of the lithium aluminum complex hydroxide carbonatesalt (LAHCS) of a lithium aluminum complex type according to thehydrated alumina gel method (Example 5 of this invention).

Furthermore, these particles have a median diameter (D₅₀) based onvolume standard, measured by a laser scattering diffraction method, ofgenerally 0.1 to 10 μm, especially 0.1 to 3 μm.

(2) Sodium Aluminum Complex Hydroxide Carbonate Salt (NAHCS)

The present inventors have found that when dawsonite which is a knownsodium aluminum basic carbonate salt mineral (basic aluminum carbonatecomplex salt) is compounded in a film-forming resin, a combination ofexcellent warmth-keeping property and transparency can be achieved, andthe compoundability in the film or the properties of the compounded filmare excellent.

FIGS. 12 and 13 respectively show infrared absorption spectra ofdawsonite (Example 12) used in this invention and hydrotalcite(Comparative Example 8) used conventionally as a resin warmth-keepingagent. According to these infrared absorption spectra, dawsonite (FIG.12) shows a spectrum near hydrotalcite (FIG. 13), but at wave numbers of1500 to 1600 (wavelengths of 0.62 to 0.66 μm), dawsonite shows largeabsorptions not observed in the hydrotalcite and clearly has excellentheat absorbability.

It has also been found that dawsonite, in a thermogravimetrc analysis,substantially has no weight loss at a temperature of 300° C. or below,and at the time of kneading or molding the resin, it is preferable toprevent foaming.

FIG. 14 is a thermogravimetric analysis curve of dawsonite used in thisinvention. The diagram in an upper side is an accumulation curve, andthe diagram in a lower side is a differential curve. The results show asurprising fact that the dawsonite used in this invention has a hydratedwater, but substantially gives no weight loss at room temperature to300° C. which exceeds the processing temperature of the resin, andtherefore, a decrease in transparency or a decrease in the properties ofa film is hardly developed by foaming which becomes a hazard at the timeof processing the resin.

Dawsonite obtained by a known production method has a fibrous shape. Ithas a fiber diameter of 0.01 to 1 μm, especially 0.01 to 0.5 μm, and anaspect ratio of 1 to 100, especially 1 to 20 which does no hampercompoundability in resins with respect to resin compositions whichattach much importance to transparency, and the transmittance of thecompounded resin becomes preferable.

NAHCS according to the hydrated alumina gel method of this invention hasa dawsonite-type crystal structure, but possesses a unique crystalstructure.

The dawsonite-type crystal structure has the substantially same X-raydiffraction pattern as shown in Table 2 below in an X-ray diffractionusing Cu-α.

                  TABLE 2                                                         ______________________________________                                        Spacing (Å)                                                                             Relative intensity                                              ______________________________________                                        5.7           vs                                                              3.38          m                                                               3.02          m                                                               2.78          S                                                               2.61          m                                                               2.5           w                                                               2.15          w                                                               1.99          m                                                               1.73          w                                                               1.69          m                                                               ______________________________________                                    

In the table, VS represents very strong, S represents strong, mrepresents moderately strong and w represents weak.

The half value width of a peak of an index of a plane (011) in an X-raydiffraction pattern in Cu-α is 0.2° or below in the dawsonite accordingto the conventional production process, but the dawsonite of the presentinvention has a half value width of a peak of an index of a plane (011)in an X-ray diffraction pattern in Cu-α of at least 0.4°, especially0.45 to 0.75°. The attached FIG. 15 shows an X-ray diffraction patternof dawsonite according to the conventional method, and FIG. 16 shows anX-ray diffraction pattern of dawsonite according to this invention.

In an X-ray diffraction pattern of crystal, it is known that when thefollowing Bragg formula (10)

    nλ=2d.sub.nkl Sin θ                           (10)

wherein n is an degree, λ is a wavelength of the X-ray, d_(hkl) is aspacing of (nkl) of a crystal, and

θ is a diffraction angle,

is satisfied, an intensity peak appears in the interference. Between thesharpness of an interference peak and the size of the crystal, therelation of the following Scherrer formula (11)

    L.sub.nkl =Kλ/H cos θ                         (11)

wherein L_(hkl) is the size in a perpendicular direction to the (hkl)surface of the crystal, K is a constant of about 0.9, H is a half valuewidth (radian) of the interference peak, and λ and θ are the same as informula (10),

is established.

That in NAHCS of this invention, the half value width of a peak of anindex of a plane (011) is large shows that the size of the crystal in ab axis direction is small.

FIG. 17 indicates a scanning-type electron microscopic photograph (amagnification 5000 times) showing a particle structure of dawsoniteaccording to a conventional method, and FIG. 18 represents ascanning-type electron microscopic photograph showing a particlestructure of dawsonite produced by the hydrated alumina gel method ofthis invention. These scanning-type electron microscopic photographsshow that the conventional dawsonite is obtained by entangling bundlesof fine fibers having an extremely large aspect ratio whereby coarsethread ball-like secondary particles are bound, but in the dawsonite ofthis invention, the degree of growth of a fibrous structure is verysmall, and the secondary particles can be a particle shape having asmall degree of agglomeration.

With regard to the particle shape, the former has a relatively largeamount of an oil absorbed of 70 to 100 ml/100 g, and the latter has anamount of an oil absorbed of 40 to 70 ml/100 g. Furthermore, the formerhas a pigment volume concentration of as low as 35% or below, but thelatter has a high pigment volume concentration of 40 to 50%.

Moreover, this particle has a volume standard median diameter (D₅₀) ofgenerally 0.1 to 10 μm, especially 0.1 to 3 μm, as measured by a laserscattering diffraction method.

Dawsonite according to this invention as already mentioned has excellentfiltrability, and has an advantage that the amount of impurity ioncontained is very small. When dawsonite is formed into an aqueous slurryhaving a concentration of 5% by weight, a conventional dawsonite has aspecific resistance generally on the order of 6000 Ω·cm, but thedawsonite according to this invention can have a specific resistance ofat least 8000 Ω·cm.

For this reason, when the dawsonite according to this invention iscompounded in a resin, etc., a deterioration of coloration, a heatdeterioration and electrical insulation by the impurity ions can besuppressed, and the excellent advantage as the resin compounding agentcan be obtained.

With respect to the above-mentioned particle structure, the dawsoniteaccording to this invention has excellent compoundability anddispersibility in resins, and furthermore, the compounded resin hasexcellent transparency. In fact, a reference to the examples to bementioned below shows that the compounded resin has a small internalhaze, and posseses excellent transparency.

FIG. 19 shows an infrared absorption spectrum of dawsonite according tothis invention. It is seen therefore that this dawsonite shows markedlywide absorptions in an infrared region, and is useful as an infraredabsorbing agent, namely a warmth-keeping agent.

The dawsonite according to this invention generally has an amount of anoil absorbed (JIS K-5101) of 50 to 110 ml/100 g, a BET specific surfacearea of 30 to 110 m² /g, and an apparent specific gravity (iron cylindermethod) of 0.1 to 0.3 g/cm³. However, these values are not limited tothe above-mentioned values.

The lithium aluminum complex-type or the dawsonite-type alkali aluminumcomplex hydroxide carbonate salt are useful as a resin compoundingagent, for example especially a warmth-keeping agent and a halogentrapping agent for resins.

Uses

LAHCS and dawsonite-type NAHCS according to this invention can becompounded in resins without any treatment. In order to modify thesurface properties of the complex salts, when these compounds aretreated in advance with not larger than 10% by weight, especially 1 to6% by weight, of a surface treating agent, it is preferred that theirdispersibility in resins increases and transmittance will further beincreased.

As the surface treating agent, silane-type, aluminum-type,titanium-type, and zirconium-type coupling agents, higher fatty acids,metal soaps, or resin acid soaps, fine powder amorphous silica andsurface active agents may be used according to the objects.

Generally, a higher fatty acid or a surface active agent is added to thereaction mother liquor containing the alkali aluminum complex hydroxidecarbonate salt, and the mixture is treated with stirring.

Examples of the higher fatty acid include saturated or unsaturated fattyacids having 10 to 22 carbon atoms, especially 14 to 18 carbon atoms,for example saturated fatty acids such as capric acid, undecanoic acid,lauric acid, myristic acid, palmitic acid, margaric acid, stearic acidand arachic acid, and unsaturated fatty acids such as linderic acid,tsuzic acid, petroselinic acid, oleic acid, linoleic acid, linolenicacid, and arachidonic acid. Stearic acid is preferred. The fatty acidsmay of course be mixed fatty acids such as beef tallow fatty acid,coconut oil fatty acid or palm oil fatty acid.

Among the surface active agents, examples of anion surface active agentsinclude primary higher alcohol sulfate ester salts, secondary higheralcohol sulfate ester salts, primary higher alkylsulfonate salts,secondary higher alkylsulfonate salts, higher alkyldisulfonate salts,sulfonated higher fatty acid salts, higher fatty acid sulfate estersalts, higher fatty acid ester sulfonate salts, sulfate ester salts ofhigher alcohol ethers, sulfonate salts of higher alcohol ethers,alkylolated sulfate ester salts of higher fatty acid amides,alkyl-benzenesulfonate salts, alkylphenolsulfonate salts,akylnaphthalenesulfonate salts and alkylbenzoimidazolesulfonate salts.More specific compounds of such surface active agents are disclosed inHiroshi Horiguchi, "SYNTHETIC SURFACE ACTIVE AGENTS" (published in 1966by Sankyo Publishing Company).

As nonionic surface active agents, there are used nonionic surfaceactive agents having a low HLB, especially an HLB of 12 or below, morepreferably an HLB of 8 or below. Generally, examples of the nonionicsurface active agents include polyoxyethylene alkyl ether,polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid esters,polyoxyethylene fatty acid amide ethers, polyvalent alcohol fatty acidesters, polyoxyethylene polyvalent alcohol fatty acid esters, fatty acidsucrose esters, alkylolamides and polyoxyalkylene block copolymers eachwith the HLB being within the above range. For example, when thepolyoxyethylene unit content of these nonionic surface active agents isdecreased, their HLB will be decreased. Therefore, by adjusting thenumber of moles of ethylene oxide added, it is possible to obtainnonionic surface active agents having the desired HLB.

The amount of the fatty acid or the surface active agent to be added maysuitably be 0.5 to 10% by weight, especially 1 to 5% by weight, based onthe alkali aluminum complex hydroxide carbonate salt.

The treating conditions are not particularly restricted, but generallythe treatment should be suitably carried out with stirring at atemperature of 60 to 100° C. for about 0.5 to 5 hours. When the fattyacid is used, the fatty acid used reacts with a sodium ion present inthe reaction system and is transferred to the aqueous phase in the formof a sodium soap, and the surface treatment of the resulting alkalialuminum complex hydroxide carbonate salt proceeds. When the anionicsurface active agent is used, a free acid which is not a salt is usedand consequently, a similar reaction takes place.

The resulting surface-treated alkali aluminum complex hydroxidecarbonate salt as it is may be used as a resin compounding agent. Asrequired, it is surface-treated with an organic or inorganic aid asbeing after-treated, and then used as a resin stabilizer or a resincompounding agent.

Examples of such organic aids are coating agents, for example, metalsoaps such as a calcium salt, a zinc salt, a magnesium salt and a bariumsalt of stearic acid, palmitic acid and lauric acid, silane couplingagents, aluminum coupling agents, titanium coupling agents and zirconiumcoupling agents, various waxes and unmodified or modified various resins(such as rosin and petroleum resins).

These coating agents may be used in an amount of 0.1 to 10% by weight,especially 0.5 to 5% by weight, based on the alkali aluminum complexhydroxide carbonate salt.

As the inorganic aids, fine particle silica such as aerosil andhydrophobic-treated aerosil, silicate salts such as calcium silicate andmagnesium silicate, metal oxides such as calcia, magnesia and titania,metal hydroxides such as magnesium hydroxide and aluminum hydroxide, ametal carbonate such as calcium carbonate, hydrotalcite, syntheticzeolites such as A type or P type, acid-treated products thereof, ortheir metal ion exchanged products thereof are exemplifiedregular-shaped particles of the inorganic aids may be used as blended orsprinkled with the alkali aluminum complex hydroxide carbonate salts, ormay be used as deposited on the surface of the alkali aluminum complexhydroxide carbonate salt particles. By treating the resulting complexhydroxide carbonate salts with the inorganic aids, the refractiveindexes of these salts may be adjusted.

These inorganic aids may be used in an amount of 0.01 to 10% by weight,especially 0.1 to 5% by weight, based on the alkali·aluminum complexhydroxide carbonate salt. When it is used as a compounding agent forresins, the refractive index of the resulting product can be matchedwith that of the resin used.

LAHCS according to this invention is useful for regin compounding agentto thermoplatic resins such as a chlorine catcher, a heat stabilizer, aninfrared absorption agent or an anti-blocking agent. Furtheremore, NAHCSis particularly useful as an infrared absorbing agent (warmth-keepingagent).

According to this invention, 0.01 to 10 parts by weight in general ofthe alkali aluminum complex hydroxide carbonate salt is compounded in100 parts by weight of a thermoplastic resin. The compounding amount mayof course be properly selected according to the type and use of theresin within the above-mentioned range.

According to one preferred embodiment of this invention, the alkalialuminum complex hydroxide carbonate salt may be used in an amount of0.1 to 10 parts by weight, especially 0.5 to 1.0 part by weight, basedon 100 parts by weight of a chlorine-containing polymer.

Examples of the chlorine-containing polymer include poly(vinylchloride), poly(vinylidene chloride), chlorinated ply(vinyl chloride),chlorinated polyethylene, chlorinated polypropylene, chlorinatedrubbers, a vinyl chloride/vinyl acetate copolymer, a vinylchloride/ethylene copolymer, a vinyl chloride/propylene copolymer, avinyl chloride/styrene copolymer, a vinyl chloride/isobutylenecopolymer, a vinyl chloride/vinylidene chloride copolymer, a vinylchloride/styrene/maleic anhydride ternary copolymer, a vinylchloride/styrene/acrylonitrile copolymer, a vinyl chloride/butadienecopolymer, a chlorinated vinyl/propylene chloride copolymer, a vinylchloride/vinylidene chloride/vinyl acetate ternary copolymer, a vinylchloride/acrylic acid ester copolymer, a vinyl chloride/maleic acidester copolymer, a vinyl chloride/methacrylic ester copolymer, a vinylchloride/acrylonitrile copolymer, an internally plasticized polyvinylchloride; and blends of these chlorine-containing polymers and α-olefinpolymers such as polyethylene, polypropylene, polybutene andpoly-3-methylbutene, polyolefins and copolymers such as anethylene/vinyl acetate copolymer and an ethylene/propylene copolymer,polystyrene or acrylic resins, copolymers of styrene with anothermonomer (such as maleic anhydride, butadiene and acrylonitrile), anacrylonitrile-butadiene-styrene copolymer, an acrylicester/butadiene/styrene copolymer or a methacrylicester/butadiene/styrene copolymer.

In this case, it is desirable to jointly use 0.01 to 10 parts by weightof a zinc salt of a fatty acid and 0.01 to 10 parts by weight of aβ-diketone or a β-keto acid ester.

Examples of the zinc salt of fatty acids may be as illustrated above.Examples of the β-diketone or the β-keto acid esters are compounds knowncoventionally in the indicated utility, and include 1,3-cyclohexadione,methylene-bis-1,3-cyclohexadione, 2-benzyl-1,3-cyclohexadione,acetyltetralone, palmitoyltetralone, stearoyltetralone,benzoyltetralone, 2-acetylcyclohexanone, 2-benzoylcyclohexanone,2-acetyl-1,3-cyclohexanedione, benzoyl-p-chlorobenzoylmethane,bis(4-methyl-benzoyl)methane, bis(2-hydroxybenzoyl) methane,benzoylacetone, tribenzoyl-methane, diacetylbenzoylmethane,stearoylbenzoylmethane, palmitoylbenzoyl-methane, lauroylbenzoylmethane,dibenzoylmethane, bis(4-chlorobenzoyl)methane,bis(methylene-3,4-dioxybenzoyl)methane, benzoylacetylphenylmethane,stearoyl(4-methoxybenzoyl)methane, butanoylacetone, distearoylmethane,acetylacetone, stearoylacetone, bis(cyclohexanoyl)-methane anddipivaloylmethane.

Of course, to use the alkali aluminum complex hydroxide carbonate saltaccording to this invention, various known additives such as stabilizersor stabilizer assistants, for example, non-metallic stabilizers, organictin-type stabilizers and basic inorganic acid salts, plasticizers,antioxidants, photostabilizers, fire retardants, nucleus-forming agents,and epoxy stabilizers may be used jointly.

Various nucleus-forming agents are conjointly used as additives in themolding of crystalline resins such as polypropylene and polyethyleneterephthalate to be mentioned to increase transparency and impactstrength or shorten the molding cycle and increase the dimensionalstability.

Furthermore, in the chlorine-containing resins, a combined use withvarious stabilizers is possible. For example, it is preferred that anorganic tin stabilizer is used in combination. Examples of the organictin compounds include organic tin mercaptides, organic tin sulfides,organic tin mercaptides sulfides, organic tin mercaptcarboxylates andorganic tin carboxylates.

(1) Examples of the organic tin mercaptides include diorganicmercaptides such as dibutyltin bis(lauryl mercaptide), dimethyltinbis(stearyl mercaptide), dioctyltin bis(mercaptoethyl tall oil fattyacid ester), dioctyltin bis(2-mercaptoethyl caprylate), dibutyltinbis(mercaptoethyl tall oil fatty acid ester), dimethyltinbis(mercaptoethyl stearate), dioctyltin bis(isooctyl thioglycolate),dioctyltin bis(2-ethylhexyl thioglycolate), dioctyltin bis(dodecylthioglycolate), dioctyltin bis(tetradecyl thioglycolate), dioctyltinbis(hexadecyl thioglycolate), dioctyltin bis(octadecyl thioglycolate),dioctyltin bis(C₁₂₋₁₆ mixed alkyl thioglycolate), dibutyltinbis(isooctyl thioglycolate), dimethyltin bis(isooctylmercaptopropionate), bis(2-mercaptocarbonylethyl)tinbis(isooctylthioglycolate), bis(2-butoxycarbonyl ethyl)tin bis(butyl thioglycolate);mono organic mercaptides such as monobutyltin tris(lauryl mercaptide),monobutyl monochlorotin bis(lauryl mercaptide),momooctyltintris(2-mercaptoethyl caprylate),monobutyltintris(mercaptoethyl tall oil fatty acid ester),monomethyltintris(mercaptoethyl tall oil fatty acid ester),monomethyl-tintris(mercaptoethyl laurate),monomethyltintris(mercaptoethyl stearate),monomethyltintris(mercaptoethyl oleate), monooctyltintris(isooctylthioglycolate), monooctyltintris(2-ethylhexyl thioglycolate),monooctyltintris(dodecyl thioglycolate), monooctyltintris(dodecylthioglycolate), monooctyltintris(tetradecyl thioglycolate),monooctyltintris(hexadecyl thioglycolate), monooctyltintris(C₁₂₋₁₆ mixedalkyl thioglycolate), monooctyltintris(octadecyl thioglycolate),monobutyltintris(isooctyl thioglycolate), monobutyltintris(isooctylmercapto propionate), monomethyltintris(isooctyl thioglycollate),monomethyltintris(tetra decyl thioglycollate), 2-methoxycarbonylethyltin tris(isooctyl thioglycollate) and2-butoxycarbonylethyltintris(2-ethylhexylthioglycollate).

(2) Examples of the organic tin sulfides include methylthiostannic acid,butylthiostannic acid, octylthiostannic acid, dimethyltin sulfide,dibutyltin sulfide, dioctyltin sulfide, dicyclohexyltin sulfide,monobutyltin sulfide, oxide, 2-methoxycarbonylethyltin sulfide,2-ethoxycarbonyltin sulfide, 2-butoxycarbonyltin sulfide,2-isopropoxycarbonylethyltin sulfide, bis(2-methoxycarbonylethyl)tinsulfide and bis(2-propoxycarbonylethyl)tin sulfide.

(3) Examples of the organic tin mercaptide sulfides includebis[monobutyl.di(isooctoxycarbonylmethylenethio)tin]sulfide,bis[dibutylmono(isooctoxycarbonylmethylenethio)tin]sulfide,bis[bis(2-methoxycarbonylethyl)tin isooctylthioglycolate] sulfide,bis(methyltin diisooctylthioglycolate) disulfide, bis(methyl/dimethyltinmono/diisooctyl thioglycolate) disulfide, bis(methyltin diisooctylthioglycolate) trisulfide, bis(butyltin diisooctyl thioglycolate)trisulfide, bis[methyltin di(2-mercaptoethyl caprylate) sulfide andbis[methyltin di(2-mercaptoethyl caprylate) disulfide.

(4) Examples of the organic tin mercapto carboxylates includedibutyltin-β-mercaptopropionate, dioctyltin-β-mercaptopropionate,dibutyltin mercaptoacetate, bis(2-methoxycarbonylethyl)tinthioglycolate, and bis(2-methoxycarbonylethyl)tin mercaptopropionate.

(5) Examples of the organic tin carobylates include aliphatic monovalentcarboxylates such as an octoate, laurate, myristate, palmitate, stearateand isostearate of a mono- or di-methyltin, mono- or di-butyltin, mono-or di-octyl-tin or mono- or bis(butoxycarbonylethyl)tin; a maleatepolymer, and a maleate such as butyl maleate, benzyl maleate, oleylmaleate, and stearyl maleate; and mixed salts or basic salts of theabove compounds.

The plasticizers include ester-type plasticizers such as phthalate estertype plasticizers and adipate ester type plasticizers, polyester-typeplasticizers, phosphate ester-type plasticizers, and chlorine-typeplasticizers.

Example of the phenol-type antioxidants include2,6-diphenyl-4-octa-desiloxyphenol,stearyl(3,5-ditert.butyl-4-hydroxyphenyl)-propionate,distearyl(3,5-di-tert.butyl-4-hydroxybenzyl) phosphonate,1,6-hexamethylene-bis[(3,5-di-tert. butyl-4-hydroxyphenyl)propionate],1,6-hexamethylenebis-[(3,5)-di-tert.butyl-4-hydroxyphenyl)proponic acidamide], bis[3,3-bis-(4-hydroxy-3-tert.butylphenyl)butyric acid]glycolester, 1,1,3-tris(2-methyl-4-hydroxy-5-tert.butylphenyl)butane,1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert.butylbenzyl) isocyanurate,1,3,5-tris(3,5-ditert butyl-4-hydroxybenzyl)isocyanurate, andtriethyleneglycol bis[(3-tertbutyl-4-hydroxy-5-methylphenyl)propionate].

Examples of the sulfur-type antioxidants includedialkylthiodipropionates such as dilauryl, dimyristyl or distearylthiopropionate, and β-alkylmercaptopropionate ester of polyol such aspentaerythritol tetra(β-dodecylmercapto-propionate).

Examples of the phosphite-type antioxidants include tris(2,4-di-tertbutylphenyl) phosphite, tris[2-tert butyl-4-(3-tertbutyl-4-hydroxy-5-methyl phenylthio)-5-methylphenyl] phosphite, tridecylphosphite, octyl diphenyl phosphite, di(decyl)monophenyl phosphite,di(tridecyl)pentaerythritol diphosphite, distearyl pentaerythritoldiphosphite, and di(nonylphenyl)pentaerythrotol diphosphite.

Examples of ultraviolet absorbing agents include 2-hydroxybenzophenonessuch as 2,4-dihydroxybenzo-phenone, 2-hydroxy-4-methoxybenzophenone and5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); and2-(2'-hydroxyphenyl)benzotriazoles such as2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert.butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tertoctylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, and 2,2'-methylenebis(4-tert octyl-6-benzotriazolyl)phenol.

Hindered amine-type photo-stabilizers may be illustrated as aphoto-stabilizer. They include 1,2,2,6,6-pentamethyl-4-piperidylstearate, 2,2,6,6-tetramethyl-4-piperidyl benzoate,N-(2,2,6,6-tetramethyl-4-piperidyl) dodecyl succinic imide,1-[(3,5-di-tertbutyl-4-hydroxyphenyl)propionyloxyethyl]-2,2,6,6-tetramethyl-4-piperidyl-(3,5-di-tertbutyl-4-hydroxyphenyl)propionate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, tetra(2,2,6,6-tetramethyl-4-piperidyl)butanetetracarboxylate,tetra(1,2,2,6,6-pentamethyl-4-piperidyl)butanetetracarboxylate,bis(2,2,6,6-tetramethyl-4-piperidyl) di(tridecyl)butanetetracarboxylateand bis(1,2,2,6,6-pentamethyl-4-piperidyl)di(tridecyl)butanetetracarboxylate.

Examples of the fire retardants include tetrabromobisphenol A (TBA),2,2-bis(4-hyroxy-3,5-dibromophenyl)propane, hexabromobenzene (HBB),tris(2,3-dibromopropyl) isocyanurate (TAIC-bB),2,2-bis(4-hydroxyethoxy-3,5-dibromo.phenyl)propane (TBA-EO),decabromodiphenyloxide (DBDPO), decabromodiphenyl ether (DBDE),1,2-bis(pentabromophenyl)ethane (PBPE),N,N'-ethylenebis(tetrabromophthalimide) (ETBP),1,2,5,6,9,10-hexabromo-cyclododecane,2,2-bis(3,5-dibromo-4-[2,3-dibromopropoxy]phenyl) propane (TBA-BP),bis(3,5-dibromo-4-[2,3-dibromopropoxy]phenyl) (TBS-BP),polydibromophenylene oxide, bis(tribromophenoxy)ethane,ethylenebis.dibromo-norbornane dicaroxyimide,dibromoethyl.dibromocyclohexane, dibromoneopentyl glycol,2,4,6-tribromophenol, tribromophenyl allyl ether, tetrabromobisphenol S,tetradecabromo.diphenoxybenzene,2,2-bis(4-hydroxyethoxy-3,5-di-bromophenyl) propane,poly(pentabromobenzyl) acrylate, tribromostyrene, tribromophenylmaleimide, tribromoneopentyl alcohol, tetrabromodipenta-erythritol,pentabromobenzyl acrylate, pentabromophenol, pentabromotoluene,pentabromophenyl oxide, hexabromocyclododecane, hexabromodiphenyl ether,octabromophenol ether, octabromophenyl ether, octabromodiphenyl oxide,dibromoneopentyl glycol tetracarbonate, bis(tribromophenyl)fumaric acidamide, N-methylhexabromo diphenylamine, halogen-containingpolyphosphate, aromatic bromine compounds, brominated epoxy resins, andbrominated polystyrene.

Examples of the nucleus-forming agents include aluminum-p-tert-butylbenzoate, dibenzylidene sorbitol, bis(4-tert.butylphenyl) phosphatesodium salt, 2,2'-methylenebis(4,6-di-tert butylphenyl)phosphate sodiumsalt, 2,2'-methylenebis(4,6-di-tert.butylphenyl) phosphate calcium saltand 2,2'-methylenebis(4,6-di-tert.butylphenyl) phosphate basic aluminumsalt.

Examples of the epoxy compounds include epoxydized soybean oil,epoxydized linseed oil, epoxydized fish oils, epoxydized tall oil fattyacid esters, epoxydized beef tallow oil, epoxydized castor oil,epoxydized safflower oil, epoxydized linseed oil fatty acid butyl,tris(epoxypropyl) isocyanurate, 3-(2-xenoxy)-1,2-epoxypropane,bisphenol-A diglycidyl ether, vinylcyclohexene diepoxide,dicyclopentadiene diepoxide and3,4-epoxycyclohexyl-6-methylepoxycyclohexanecarboxylate.

In another typical use of this invention, the alkali aluminum complexhydroxide carbonate salt is compounded in an olefin resin in order toprevent the deterioration of the resin due to the halogen-type catalystresidues. The compounding agent of the present invention may be usedpreferably in an amount of 0.01 to 10 parts by weight per 100 parts byweight of the olefin resin. Examples of the olefin type resins includepolypropylene, low-, medium-, and high-density or linear low-densitypolyethylenes, a crystalline propylene/ethylene copolymer, ionicallycrosslinked olefin copolymers, an ethylene/vinyl acetate copolymer, anethylene/acrylate copolymer, a low-density ethylene/butene-1 copolymerand a low-density ethylene/hexene-1 copolymer. The olefin type resinsinclude those synthesized by using metallocene catalysts.

In still further usages of this invention, the alkali aluminum complexhydroxide carbonate salt is compounded in an amount of 1 to 30 parts byweight per 100 parts by weight of an olefin resin for the formation ofan agricultural film together with an anticlouding agent. The olefinresin suitably includes the above illustrated resins.

The present invention will be illustrated by citing Examples, but theinvention is not limited by such examples.

EXAMPLES

Fine powders of the alkali aluminum complex hydroxide carbonate salts,such as a lithium aluminum complex hydroxide carbonate salt (LAHCS), asodium aluminum complex hydroxide carbonate salt (dawsonite-type NAHCS)and a lithium sodium aluminum complex hydroxide carbonate salt (mixedcrystal, LNAHCS), methods of producing these carbonate salts, and theiruses will be explained below.

Measuring Methods (1) X-Ray Diffraction

The X-ray diffraction was measured by using Geigerflex (goniometer: CatNo. 2125D1) made by Rigaku Co. under the following conditions.

    ______________________________________                                        Target              Cu                                                        Filter              Ni                                                        Detector            SC                                                        Voltage             35 KV                                                     Current             15 mA                                                     Count flull scale   8000 c/s                                                  Scanning speed      2 deg/min.                                                Time constant       1 sec                                                     Slit                DS 1 deg. RS 0.3                                                              mm SS 1 deg                                               Irradiation         6 degree                                                  ______________________________________                                    

(2) Lamination Asymmetry Index (Is)

The index was measured by using Geigerflex (goniometer: Cat No. 2125D1)made by Rigaku Co. under the following conditions.

    ______________________________________                                        Target              Cu                                                        Filter              Ni                                                        Detector            SC                                                        Voltage             40 KVP                                                    Current             20 mA                                                     Count full scale    1000 c/s                                                  Scanning speed      1 deg/min.                                                Time constant       1 sec                                                     Slit                DS 1 degree RS 0.3                                                            mm SS 1 deg                                               Irradiation         6 deg                                                     Measured diffraction angles                                                                       35 to 55 (2 θ degree)                               ______________________________________                                    

The method of calculating the lamination asymmetry index(Is) comprisesdrawing peak tangents (a, b) on a narrow angle side and a broad angleside with respect to both peaks at diffraction angles (2θ) of 36° to 44°and 44° to 53° obtained by the above X-ray diffractions so that theabsolute values of the inclinations become maximum. Next, aperpendicular c is drawn from a point of intersection between the peaktangent a on the narrow angle and the peak tangent b on the broad angle.Thus, an angle θ₁ formed between the tangent a and the perpendicular cand an angle θ₂ formed between the tangent b and the perpendicular c aremeasured, and the lamination asymmetry index (Is) is measured from thefollowing formula.

    Is=tan θ.sub.2 /tan θ.sub.1

(3) Orientation Degree (OD)

The orientation degree (OD) is defined by the following formula

    OD=I(002)/I(110)

wherein I(002) is a relative intensity of a peak in an X-ray diffraction(Cu-Kα) appearing in an index of the plane (002) at a spacing (d) of7.67 to 7.84 Å, and I(110) is a relative intensity of a peak in an X-raydiffraction (Cu-Kα) appearing in an index of the plane (110) at aspacing (d) of 4.41 to 4.45 Å.

(4) Thermal Analysis

A measurement sample was in advance treated with ethyl alcohol to removethe surface treating agent, and dried at 110° C. by using a constanttemperature dryer. Then, the thermal analysis was carried out by usingTAS100-TG8110 thermal analysis system made by Rigaku Co. The measuringconditions included α-Al₂ O₃ as a standard substance, a temperatureraising speed of 10° C./min. and air as an atmosphere, and under theabove conditions, and a weight decrease ratio was measured at atemperature of 250° C. or below.

(5) Infrared Absorption Spectrum Analysis

A measuring sample was in advance treated with ethyl alcohol to removethe surface treating agent, and dried at 110° C. by using a constanttemperature dryer. Then, the measurement was carried out by using anA-302 type infrared absorption spectrum analyzing instrument made byNippon Bunko Co.

(6) Fiber Diameter and Aspect Ratio

Using a scanning electron microscope (S-570) made by Hitachi Co, thefiber diameter in a restricted visual image and the aspect ratio werecalculated.

(7) Apparent Density

Measured in accordance with JIS K-6220.

(8) Amount of an Oil Absorbed

Measured in accordance with JIS K-5101-19.

(9) Specific Surface Area

Using Sorptomatic Series 1900 made by Carlo Erba Co., a specific surfacearea by BET was measured.

(10) Average Particle Diameter

The average particle diameter (median diameter: μm) was measured byusing a laser diffraction-type particle size analyzer (Coulter RLS130)produced by Coulter Counter Co.

(11) Pigment Volume Concentration

DOP (dioctyl phthalate) was used as a vehicle, and the concentration wascalculated by the following formula.

Pigment volume concentration=100Bρ/(Bρ+0.01 Or Pρ)

Bρ: the density (g/ml) of the resin (vehicle), (DEP: 0.9861)

Pρ: the density (g/ml) of the sample

Or: the amount of an oil absorbed in the sample (ml/100 g)

A Process by the Migration Method and the Properties of the ProductExample 1

Gibbsite-type hydrated alumina (Hidilight H-42 produced by Showa DenkoCo., Ltd.=617.5 g) having an average particle diameter of 1.4 μm and148.6 g of lithium carbonate were charged in 3.5 liters of ion exchangedwater placed in 10 liters of a stainless steel container so that asalumina (Al₂ O₃), the concentration became 10% (hereinafter weight %otherwise stated). The mixture was heated to 90° C. with stirring andreacted for 4 hours. The solid concentration of the resulting LAHCS was16%, and the pH at the end of the reaction was 10.5. Thereafter, 18.2 gof sodium stearate was added under heating with stirring to perform thesurface treatment for about 2 hours. After filtration, the product wasdried at 110° C., and pulverized and classified to give 617 g of apowder of LAHCS as a sample No. 1. In this Example, the amount of acarbonic acid ion based on the entire aluminum atoms in the reactionsystem was 0.17 mole.

Example 2

In the same way as in Example 1, a LAHCS powder as a sample No. 2 wasobtained by the same method of Example 1 except that sodium carbonateand lithium chloride were used instead of the lithium carbonate inExample 1. In this Example, the product was filtered and thereafter,washed thoroughly with ion exchanged water.

Example 3

Gibbsite-type hydrated alumina was classified to obtain a gibbsitehydrated alumina having an average particle diameter of 0.6 μm andcontaining 0.5% of particles having a particle size of at least 20 μmand a gibbsite hydrated alumina having an average particle diameter of4.8 μm and containing 1.8% of particles having a particle size of atleast 20 μm, as starting materials. Powders of LAHCS were obtained inthe same way as in Example 1 except that these starting materials wereused. The products were samples Nos. 3 and 4. The solid concentrationsof these LAHCS samples were 11.5% and 18.5% respectively.

Example 4

Example 1 was repeated except that a gibbsite-type hydrated aluminahaving an average particle diameter of 0.6 μm and containing 1.8% ofparticles having a particle size diameter of at least 20 μm was used asa starting material and hydrothermal treatment was performed at areaction temperature of 130° C. Otherwise, Example 1 was repeated in thesame way as mentioned above to give an LAHCS powder. The product was asample No. 5. Incidentally, the reaction time was 2 hours.

Comparative Example 1

A commercially available gibbsite-type hydrated alumina having anaverage particle diameter of 4.8 μm and containing 4.8% of particleshaving a particle size of at least 20 μm was used as a startingmaterial. Otherwise, a LAHCS powder was prepared in the same way as inExample 1 to give a sample No. H-1.

Comparative Example 2

An LAHCS powder was prepared in the same way as in Example 1 except thatin Comparative Exampe 1, the average particle diameter was 6 μm and theamount of particles having at least 20 μm was 4.5%. The resultingproduct was referred to as a sample No. H-2.

Comparative Example 3

24.08 g of sodium hydroxide (96% of NaOH) and 3.73 g of sodium carbonate(99% of Na₂ CO₃) were added to 2.3 liters of distilled water withstirring, and the solution was heated at 40° C. To this aqueous solutionwas gradually poured an aqueous solution prepared by adding 49.78 g ofaluminum chloride (20.48% of Al₂ O₃) to 250 mL of distilled water sothat the mole ratio of CO₃ /Li became 2. Furthermore, the reaction wasperformed with stirring at 90° C. for 15 hours. Then, the reactionmixture was filtered, washed with water, and again dispersed indistilled water to give a slurry of LAHCS having a solid concentrationof 2.33%.

Then, oleic acid was added in an amount of 5% based on the LAHCS solidcontent, and the product was stirred and surface-treated. Thereafter,the product was filtered, dried at 60° C. and pulverized by a smallsample mill to give an orientation enhancer-treated LAHCS, a sample No.H-3.

Comparative Example 4

24.08 g of sodum hydroxide (96% of NaOH), 2.13 g of sodium carbonate(99% of Na₂ CO₃), and 2.73 g of lithium carbonate (99% of LiCO₃) wereadded to 2.3 liters of distilled water with stirring, and the solutionwas heated to 40° C. Then, to this aqueous solution was gradually pouredan aqueous solution prepared by adding 49.78 g of aluminum chloride(20.48% of Al₂ O₃) to 250 mL of distilled water so that the CO₃ /Li moleratio became 2. The pH after pouring of the aqueous solution was 10.1.Furthermore, the reaction was performed for 15 hours at a temperature of90° C. with stirring to give a LAHCS slurry having a solid concentrationof 3.5%.

Thereafter, the product was filtered, dried at 70° C., and pulverized bya small sample mill to give an orientation enhancer-treated LAHCS as asample No. H-4.

                                      TABLE 3                                     __________________________________________________________________________    Sample No.     1   2   3   4   5   H-1 H-2 H-3 H-4                            __________________________________________________________________________    Lamination asymmetry index                                                                   0.605                                                                             0.61                                                                              0.753                                                                             0.825                                                                             0.332                                                                             1.302                                                                             1.461                                                                             1.438                                                                             1.452                          Degree of orientation                                                                        6.35                                                                              7.22                                                                              6.53                                                                              6.62                                                                              6.48                                                                              7.56                                                                              6.83                                                                              46.80                                                                             47.30                          Average particle diameter (μm)                                                            2.7 2.8 2.6 2.7 2.7 5.5 4.4 3.5 3.8                            Apparent specific gravity (g/ml)                                                             0.259                                                                             0.258                                                                             0.259                                                                             0.259                                                                             0.258                                                                             0.320                                                                             0.120                                                                             0.112                                                                             0.113                          Oil absorption amount (ml/100 g)                                                             45  45  45  45  45  26  71  68  70                             Specific surface area (m.sup.2 /g)                                                           9.74                                                                              9.82                                                                              9.76                                                                              9.80                                                                              9.86                                                                              2.30                                                                              25.6                                                                              25.7                                                                              26.3                           Pigment volume concentration (%)                                                             52.7                                                                              52.7                                                                              52.7                                                                              52.7                                                                              52.7                                                                              --  --  42.4                                                                              41.7                           Dispersibility (number/m.sup.2)                                                              1   1   1   1   1   43  38  1   1                              Transparency (%)                                                                             87  87  87  87  87  75  72  82  84                             Chlorine trapping property (min)                                                             85  85  85  85  85  32  36  80  81                             __________________________________________________________________________

Process by the Hydrated Alumina Gel Method, the Product and itsProperties Example 5

789.4 g of aluminum sulfate (7.75% of Al₂ O₃) was added to distilledwater to prepare 700 mL of an aqueous solution. Separately, distilledwater was added to 188.4 g of sodium carbonate (99.7% of Na₂ CO₃) toprepare 700 mL of an aqueous solution. Two hundred mL of warm water at60° C. was added to a 2-liter beaker and with stirring, the abovedistilled waters were added simultaneously. Furthermore, 2 g of sodiumhydroxide was added to the above mixture to adjust the pH of the aqueoussolution to 10. The mixture was heated to 60° C. to obtain apseudo-boehmite type hydrated alumina gel having a concentration of 3.6%as alumina (Al₂ O₃).

Thereafter, 22.4 g of a lithium carbonate powder was added to the slurrysolution so that the Al/Li mole ratio became 2 (or the carbonic acid ionbased on the total aluminum atoms became 0.67 mole ratio), and thereaction was performed at 90° C. for 10 hours. The pH after addition was10.1. After the end of the reaction, 12.1 g of stearic acid was added,and the surface of the product was treated by stirring. The resultantreaction suspension was filtered, washed with water, dried at 110° C.and pulverized with a small sample mill to give a lithium aluminumcomplex-type LAHCS (yield 98.6%) as a sample No. 6.

Example 6

Distilled water was added to 352 g of an aqueous solution of sodiumaluminate (containing 23.7% of Al₂ O₃) to prepare 700 mL of an aqueoussolution and the solution was heated to 50° C. With stirring, 566.7 g ofaluminum sulfate (7.78% of Al₂ O₃) and distilled water were added to theheated solution to prepare 800 mL of an aqueous solution and to give anamorphous hydrated alumina gel.

Thereafter, 14.62 g of sodium hydroxide was added to the slurry toadjust the pH to 10. Thereafter, 46.65 g of a powder of lithiumcarbonate (99% of LiCO₃) was added so that the Al/Li mole ratio wasadjusted to 2, and thereafter the mixture was reacted at 90° C. for 10hours. After the addition, the pH was 10.1. After the reaction, 15.1 gof stearic acid was added, and with stirring, the surface-treatmentreaction was carried out. Thereafter, by the same operation as inExample 1, a mixed crystal composed of LAHCS and dawsonite-type NAHCSwas obtained as LNAHCS as a sample No. 7 (yield 91.5%).

Comparative Example 5

Fifty grams of a commercially available gibbsite-type aluminum hydroxide(average particle diameter of 0.5 μm) was placed in 200 ml of a 20%aqueous solution of lithium chloride, and the mixture was hydrothermallyreacted at 115° C. for 2 hours. Thereafter, 4 g of sodium stearate wasadded, and with stirring, the surface-treatment was carried out. Then,by the same operation as in Example 1, a sample No. H-5 was obtained.X-ray diffraction showed that the resulting product was a mixture ofLiCl.2Al(OH)₃.nH₂ O and gibbsite.

Comparative Example 6

Distilled water (400 ml) was put in advance in a 2-liter beaker, and 500ml of a 1 mol/l aqueous solution of aluminum chloride and 500 ml of a 4mol/l aqeuous ammonia were simultaneously added with stirring at roomtemperature to give a sol of hydrated alumina. The pH of the resultingsuspension was 8.2. The reaction suspension was filtered and washed withwater over one week to obtain an amorphous hydrated alumina gel.

To the resulting aqueous slurry of hydrated alumina gel, 10.5 g oflithium hydroxide (monohydrate) was added, and the mixture was reactedat 95° C. for 8 hours. By the same operation as in Comparative Example1, a sample No. H-6 was obtained except that 2.7 g of stearic acid wasadded. X-ray diffraction showed that the resulting product was a mixtureof Li₂ CO₃.4Al(OH)₃.nH₂ O and nordstrandite-type aluminum hydroxide.

                  TABLE 4                                                         ______________________________________                                        Sample No.    6           H-5     H-6                                         ______________________________________                                        Specific surface                                                                            51          53      20                                          area (m.sup.2 /g)                                                             Apparent density                                                                            0.105       0.287   0.119                                       (g/ml)                                                                        Oil absorption                                                                              65          50      55                                          amount (ml/100 g)                                                             Lamination asymmetry                                                                        0.65        obscure 0.71                                        index (about 40 deg)                                                          Lamination asymmetry                                                                        0.65        obscure 0.93                                        index (about 48 deg)                                                          Pigment volume                                                                concentration (%)                                                                           43.5        --      --                                          ______________________________________                                    

Example 7

Distilled water was added to 789.4 g of aluminum sulfate (containing7.75% of Al₂ O₃) to prepare 700 mL of an aqueous solution. Separately,distilled water was added to 188.4 g of sodium carbonate (containing99.7% of Na₂ CO₃) to prepare 700 mL of an aqueous solution. Theseaqeuous solutions were simultaneously added to 200 mL of warm water at60° C. which was stirred in a 2-liter beaker to obtain an amorphoushydrated alumina gel.

Then, 101.8 g of a powder of sodium hydrogencarbonate (containing 99% ofNaHCO₃) was added to the slurry solution so that the mole ratio of CO₃/Al became 1. Then, the mixture was reacted at 90° C. for 2 hours. ThepH after the addition was 8.8. After the reaction, 12.1 g of stearicacid was added, and the surface-treatment reaction was carried out.Thereafter, by the same operation as in Example 1, dawsonite-type NAHCSas a sample No. 8 was obtained in a yield of 99.2%.

Example 8

Distilled water was added to 789.4 g of aluminum (containing 7.75% ofAl₂ O₃) to prepare 700 mL of an aqueous solution. Separately, distilledwater was added to 188.4 g of sodium carbonate (containing 99.7% of Na₂CO₃) to prepare 700 mL of an aqueous solution. These aqeuous solutionswere added simultaneously to 200 mL of warm water at 60° C. in a 2-literbeaker with stirring. Furthermore, sodium hydroxide was added to adjustthe pH to 9. The mixture was heated at 60° C. to give a pseudoboehmitetype hydrated alumina gel.

Then, 101.8 g of sodium hydrogen carbonate (containing 99% of NaHCO₃)was added so that the CO₃ /Al mol ratio was adjusted to 3. Then, theaqueous solution was reacted at 90° C. for 2 hours. After the reaction,the pH was 10.1. After the end of the reaction, 12.1 g of stearic acidwas added, and with stirring, the surface treatment reaction was carriedout. Thereafter, by the same operation as in Example 1, dawsonite-typeNAHCS was obtained as a sample No. 9 (yield 98.7%).

Example 9

Basic aluminum sulfate was added dropwise to an oil heated at 85° C.,and thereafter, 789.5 g of amorphous hydrated alumina gel (water content91%, and 75% of Al₂ O₃) obtained by thorough washing was put in a2-liter beaker, and distilled water was added to prepare 1500 ml of anaqueous solution. Then, 252 g of a powder of sodium hydrogen carbonate(99% of NaHCO₃) was added so that the CO₃ /Al was adjusted to 3, andthereafter, the mixture was reacted at 90° C. for 2 hours. After theaddition, the pH was 8.8. After the end of the reaction, 12.1 g ofstearic acid was added, and the surface-treatment reaction was carriedout with stirring. Thereafter, by the same operation as in Example 1,dawsonite-type NAHCS as a sample No. 10 was obtained in a yield of98.8%.

Example 10

Distilled water was added to 934.1 g of aluminum sulfate (containing7.75% of Al₂ O₃) to prepare 800 mL of an aqueous solution. Separately,distilled water was added to 221.5 g of sodium carbonate (99.7% of Na₂CO₃) to prepare 800 mL of an aqueous solution. Warm water (200 mL) at60° C. was added to a 2-liter beaker, and with stirring, the aboveaqueous solutions were simultaneously added to give amorphous hydratedalumina gel.

Then, 119.3 g of sodium hydrogen carbonate (99% of NaHCO₃) was added tothe slurry solution so that the Co₃ /Al mole ratio became 1. Thereafter,the mixture was reacted at 90° C. for 2 hours. Furthermore, 2 g ofsodium hydroxide was added to adjust the pH to 10, and then 6.6 g of apowder of lithium carbonate was added so that the Al/Li mol ratio became8. After the addition, the pH was 10.1. After the reaction, 12.1 g ofstearic acid was added, and with stirring, the surface-treatmentreaction was carried out. Thereafter, by the same operation as inComparative Example 1, a mixed crystal composed of a lithium aluminumcomplex type and a dawsonite-type as a sample No. 11 (LNAHCS; yield97.8%) was obtained.

Comparative Example 7

88.8 g of sodium hydroxide (containing 96% of NaOH), 84.0 g of sodiumhydrogen carbonate (containing 99% of NaHCO₃) and 600.6 g of urea(containing 97% of NH₂ CONH₂) were dissolved in 1815 g of an aqueoussolution of sodium aluminate (Al₂ O₃ =2.8%, Na₂ O=2.3%) with stirring.This mixed solution was heated at 90° C. and further reacted at 90° C.for 20 hours with stirring. After the end of the reaction, 7.2 g ofsodium oleate was added and the surface-treatment reaction was carriedout. Thereafter, by the same operation as in Comparative Example 1,dawsonite-type basic aluminum carbonate complex salt as a conventionalneedle-like crystal as a sample No. H-7 was obtained.

                  TABLE 5                                                         ______________________________________                                        Sample No.   8       9       10    11    H-7                                  ______________________________________                                        Half width of                                                                              0.46    0.66    0.53  0.50  0.30                                 hkl (011)[deg]                                                                Average particle                                                                           0.85    0.86    0.86  0.86  0.36                                 diameter (μm)                                                              Aspect ratio 1.2     1.5     1.6   1.3   40                                   Apparent density                                                                           0.25    0.29    0.28  0.25  0.18                                 (g/ml)                                                                        Amount of an oil                                                                           54      54      54    60    92                                   absorbed (ml/100 g)                                                           Specific surface                                                                           52      70      57    50    31                                   area (m.sup.2 /g)                                                             Weight decrease (%)                                                                        3.8     4.8     4.4   3.7   2.3                                  at ˜250° C.                                                      Pigment volume                                                                             42.9    42.9    42.9  --    30.6                                 concentration (%)                                                             ______________________________________                                    

A Process for Producing a Conventional Method Dawsonite for Preparationof a Warmth-Keeping Agent and its Properties

In the following Examples, dawsonite for evaluating a resinwarmth-keeping agent was prepared by a conventional method.

Example 11

46.78 g of sodium carbonate (99.7% of Na₂ CO₃) was added to 400 ml ofdistilled water with stirring, and the resulting aqueous solution washeated to 40° C. Then, 400 ml of an aqueous solution containing 48.29 gof aluminum chloride (containing 97% of AlCl₃.6H₂ O) was graduallypoured, and with stirrring, the mixture was reacted at 85° C. for about20 hours. Thereafter, 1.44 g of stearic acid was added, and withstirring, the surface-treatment was carried out. Thereafter, theslurry-like product was filtered, washed with water, dried at 70° C. andpulverized by a small sample mill to give a resin warmth-keeping agentin accord-with this invention as a sample No. 12.

Example 12

88.8 g of sodium hydroxide (containing 96% of NaOH), 84 g of sodiumhydrogen carbonate (containing 99% of NaHCO₃) and 600.6 g of urea(con-taining 97% of NH₂ CONH₂) were dissolved with stirring in 1815 g ofan aqueous solution of sodium aluminate (2.8% of Al₂ O₃, and 2.3% of Na₂O). Then, the resulting solution was heated to 90° C. with stirring andreacted for 20 hours. Thereafter, 7.2 g of sodium oleate was added toperform surface-treatment. Then, by the same method as in Example 1, aresin warmth-keeping agent of this invention was obtained as a sampleNo. 13.

Comparative Example 8

37.0 g of sodium hydroxide (containing 96% of NaOH) and 11.16 g ofsodium carbonate (containing 99.7% of Na₂ CO₃) were added to 2 liters ofdistilled water with stirring, and heated to 40° C. Then, an aqueoussolution prepared by adding 61.28 g of magnesium chloride (19.73% ofMgO) and 37.33 g of aluminum chloride (20.48% of Al₂ O₃) to 500 ml ofdistilled water was gradually poured so that the CO₃ /Na mol ratiobecame 0.7, and the Mg/Al mol ratio became 2.0. With stirring, themixture was reacted at 90° C. for 20 hours. After the end of thereaction, 3.27 g of stearic acid was added, and with stirring, thesurface treatment was performed. In the same way as in Example 11, ahydrotalcite powder was obtained as a sample H-8.

                  TABLE 6                                                         ______________________________________                                        Sample No.    12         13      H-8                                          ______________________________________                                        Fiber diameter                                                                              3(30)      10(60)  1(1.5)                                       (aspect ratio)                                                                Apparent specific                                                                            0.16       0.13   0.24                                         gravity                                                                       Oil absorption amount                                                                       65         92      66                                           Specific surface area                                                                       64         31      36                                           Heat weight loss                                                                            6.1        2.2     11.5                                         (110-250° C.)                                                          ______________________________________                                    

As is clear from the heat weight loss value described in FIG. 11 andTable 6, when the warmth-keeping agent of this invention is comparedwith the hydrotalcite powder (sample No. H-8) utilized heretofore as aresin warmth keeping agent, the warmth-keeping agent of this inventionis characterized in that its weight loss at a temperature region of 300°C. or below is outstandingly low.

APPLICATION EXAMPLES

In the following application example,

the heat stability effect, when a stabilizer or warm-keeping agent of analkali aluminum complex hydroxide carbonate salt (lithium aluminumcomplex type or dawsonite type) obtained in Example 1 to 12 iscompounded into a chlorine containing resin;

the resin stability (yellowness preventing effect, halogen capturingproperty) and the dispersibility in a resin, when the stabilizer orwarm-keeping agent is compounded into a polyolefin resin comprising ahalogen-containing catalyst residue; and further

the warmth-keeping effect in an ethylene/vinyl acetate copolymer resin;

will be explained.

Testing Method (12) V.R and H.T

The volume resistance (V.R) and the heat stability (H.T) [Congo Red testpaper] of a sheet were tested in accordance with JIS K6723. A sheet wasprepared under the same conditions and pressed at 190° C. to produce asheet having a thickness of 1 mm, and its coloring properties(whiteness, color difference, yellowness) were measured.

(13) Heat Stability Duration Test

A sample sheet was placed on a glass plate and put in a Geer's heataging tester adjusted to 185° C. and taken up every 15 minutes. Thecoloration degree was evaluated with the eye, and the time required forcompleting a black decomposition was measured.

(14) Blocking Property

Two pieces of films were overlapped one upon the other, left to stand at40° C. under a load of 200 g/cm² for 24 houes, and their peeling wasevaluated as follows.

O: Peel without resistance.

O: Peel with slight difficulty.

Δ: Peel with difficulty.

X: Peel with considerable difficulty.

(15) Fish Eye

By observation with an optical microscope, the number of at least 0.1 mmin 400 cm² of a film was measured.

(16) Scratch Property

A load of 10 kg was applied to a film having a section of 10×10 and wasrubbed three times. A scratch prioerty was sought from a haze differencebefore and after the rubbing.

(17) Transparency

A white light transmission factor of a sample sheet was measured byusing a 1001 DP color-difference meter manufactured by Nippon DenshokuKogyo Co., Ltd.

(18) Yellowness Resistance Test

The above molded sheet was put into a constant temperature constanthumidity tank kept at 85° C. and 90% RH and left to stand for 24 days.The surface color phase of the molded sheet was measured by acolor-difference meter Model 1001 DP manufactured by Nippon DenshokuKogyo Co., Ltd. and an N value (yellowness degree) was sought. As the Nvalue is smaller, the yellowness degree resistance is better.

(19) Haze

Evaluated in accordance with ASTM-D-1003.

(20) Warmth-Keeping Property

A tunnel frame with a semicircular cylinder having a diameter of 20 cmand a length of 1 m was constructed with the above sample film andplaced over the ground, and the temperature of the central portion ofthe tunnel frame was measured at night (at 3 o'clock in the morning).Based on the temperature of a tunnel frame made from an EVA film whichdid not contain a warmth-keeping agent as a standard, a temperaturedifference (ΔT) was measured to evaluate a warmth-keeping effect. In thepresent invention, as the ΔT value is larger, the warmth-keeping effectis higher.

Application Example 1

A polypropylene sheet in which the lithium aluminum complex-type resincompounding agent LAHCS was compounded was prepared, and evaluated.

Compounding

    ______________________________________                                        Polypropylene resin                                                                                100 parts by weight                                      (Hipole F657P)                                                                Di-tertiary butyl  0.15 part by weight                                        para-cresol                                                                   Silton JC-30 (AB agent                                                                           0.05 part by weight                                        made by Mizusawa Chemicals)                                                   Stearic acid Ca     0.1 part by weight                                        ______________________________________                                    

Method of Molding

A sample was added to the resulting compounded composition and they weremixed by a supermixer for 1 minute. By using a monoaxial extruder, theresulting mixture was pelletized at 220° C., and a crude film wasprepared by T-die forming. Then, the film was stretched 6 times in avertical direction and 12 times in a transverse direction by a biaxialstretching-type molding machine to obtain a biaxially stretched filmhaving a thickness of 15 μm. The results of the application example areshown in Tables 7 and 8.

                  TABLE 7                                                         ______________________________________                                                Yellowness resistance                                                                            Heat aging test                                            (N value)          (N value)                                          Sample    1 time   3 times     initial                                                                            after                                     No.       extrusion                                                                              extrusion   value                                                                              5 hours                                   ______________________________________                                        1         5.1      11.3        12.2 22.6                                      H-2       7.5      16.5        16.5 30.6                                      H-3       6.8      15.4        17.3 28.1                                      ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                                 Amount                          Scratch                              Sample   compounded                                                                              Haze     AB    Fish   property                             No.      (ppm)     (%)      property                                                                            eye    (%)                                  ______________________________________                                        1        800       1.6      ◯                                                                       none   0.2                                  2        800       1.5      ◯                                                                       none   0.2                                  3        800       1.7      ◯                                                                       none   0.2                                  4        800       1.7      ◯                                                                       none   0.1                                  5        800       1.6      ◯                                                                       none   0.2                                  H-2      800       3.5      ◯                                                                       4      0.4                                  H-3      800       3.8      ◯                                                                       3      0.4                                  ______________________________________                                    

Application Example 2

To confirm the heat stabilizing effect of the lithium aluminumcomplex-type resin stabilizer LAHCS on a vinyl chloride resin, a softvinyl chloride resin sheet was prepared in accordance with the followingrecipe for compounding and the following molding method, and subjectedto the following evaluation tests.

Recipe for Compounding

    ______________________________________                                        Vinyl chloride resin 100    parts by weight                                   (degree of polymerization: 1050)                                              Dioctyl phthalate    50     parts by weight                                   Epoxidized soybean oil                                                                             3      parts by weight                                   Sample (sample No. 1)                                                                              1.3    parts by weight                                   Zinc stearate        0.4    part by weight                                    bis Phenol A         0.2    part by weight                                    1,4-Butanediolbis    0.1    part by weight                                    ______________________________________                                    

Molding Method

The above compounded composition was kneaded by a roll mill at 150° C.for 6 minutes to prepare a uniform mixed product having a thickness of0.5 mm. Then, the mixed product was heated at 170° C. under a pressurefor 5 minutes to prepare a soft vinyl chloride resin sheet having athickness of 1 mm, and its heat stabilizing effect, etc. were evaluated.

As a result, the product had a H.T of 137 minutes, a V.R of 1×10¹³, a Wof 88.8, a ΔE of 8.3, and a ΔN of 9.9. When a coloring preventing agentwas not used, the product had a H.T of 90 minutes, and a V.R of0.83×10¹³. Incidentally, the coloration degree of the sheet was measuredby a color-difference meter of 1001 DP (whiteness degree W, colordifference ΔE, and yellowness degree ΔN) manufactured by Nippon DenshokuKogyo Co., Ltd.

Application Example 3

A resin stabilizer (sample No. 1) in accordance with this invention wascompounded in a chlorinated vinyl chloride resin which was particularlyused in a high heat-resistance high temperature region, and the heatstabilization effect of the resin stabilizer was evaluated. The resultsare shown in Table 9.

Compounding

    ______________________________________                                        Chlorinated vinyl chloride resin                                                                   100    parts by weight                                   Mercapt Sn-type stabilizer                                                                         0.7    part by weight                                    Ester-type wax       1      part by weight                                    Sample               1.05   parts by weight                                   ______________________________________                                    

Molding Method

The above compounded composition was mixed by a roll mill at atemperature of 160° C. for 7 minutes to prepare a uniform mixture havinga thickness of 0.4 mm. Then, the mixture was heated at a temperature of180° C. under a pressure of 150 kg/cm² for 5 minutes to prepare achlorinated vinyl chloride plate having a thickness of 1 mm, and a heatstabilizing effect was evaluated. The test plate was suspended in aGeer's color heat aging tester adjusted at a temperature of 190° C., andtaken out every 10 minutes. The coloration degree of the test plate wasevaluated by observation with eyes, and the time required until theplate was decomposed in dark brown was measured. The coloration degreewas evaluated in a scale of 5 stages, and the results are shown in Table9.

                  TABLE 9                                                         ______________________________________                                                    Heat stabilization                                                            duration/evaluation stages                                                    (1-5) (minutes)                                                   Sample type (No.)                                                                           10    20      30  40    50  60                                  ______________________________________                                        No. 1         1     1       2   2     2   4                                   Blank         1     2       2   5                                             Hydrotalcite  1     2       5                                                 Calcium stearate                                                                            1     4       5                                                 ______________________________________                                    

Application Example 4

With respect to dawsonite in accordance with a conventional method whichwas used in this invention, the following tests were performed.

4-1: Evaluation by a Soft Vinyl Chloride Resin

To confirm the heat stabilization effect on a vinyl chloride resin by aresin stabilizer of this invention, a soft vinyl chloride resin sheetwas prepared in accordance with a compounding recipe and a moldingmethod, and evaluated.

Compounding Recipe

    ______________________________________                                        Vinyl chloride resin                                                                              100    parts by weight                                    (polymerization degree: 1050)                                                 Di-octyl phthalate  50     parts by weight                                    Zinc laurate        0.4    part by weight                                     Dibenzoyl methane   0.1    part by weight                                     Dihydroxydiphenyl propane                                                                         0.2    part by weight                                     Sample (sample No. 12)                                                                            1.3    parts by weight                                    ______________________________________                                    

Molding Method

The above compounded composition was kneaded by a roll mill at atemperature of 150° C. for 7 minutes to prepare a uniform mixture havinga thickness of 0.5 mm. Thereafter, the mixture was heated at atemperature of 160° C. under a pressure of 130 kg/cm² for 5 minutes toprepare a soft vinyl chloride resin sheet, and the heat stabilizingeffect, etc. were evaluated.

As a result, with regards to the warmth-keeping agent for resin of thepresent invention, the time required to reach black decomposition was 90to 110 minutes, and the sheet had a transparency (transmission %) of 89to 90%. When this warmth-keeping agent was added to the soft vinylchloride resin, an excellent heat stabilization effect and an excellenttransparency holding property were exhibited.

4-2: Evaluation by a Polypropylene Resin

To confirm a yellowness-preventive effect and a rust-preventive effectof polypropylene resin by a resin stabilizer of this invention, apolypropylene sheet was prepared in accordance with the following recipeby the following molding method, and evaluated.

Compounding Recipe

    ______________________________________                                        Polypropylene resin containing                                                                     100    parts by weight                                   a halogen-remaining catalyst                                                  residue                                                                       Sample (sample No. 12)                                                                             0.3    part by weight                                    bis Phenol A         0.1    part by weight                                    ______________________________________                                    

Molding Method

The above compounded composition was pelletized by using an extruder at260° C. This sample pellet was placed in a metal frame of a stainlesssteel plate having a thickness of 1 mm, a length of 100 mm and a widthof 100 mm, sandwiched between a thick ferro-type plate for photographyand a 2-mm thick aluminum plate, and pressed at 230±3° C. for 30minutes. The processed pellet was moved to a cooling press at 30±5° C.,and cooled under a pressure of about 50 kg/cm² based on a molding planeof projection. After the mold became lower than 40° C., a polypropylenesheet having a thickness of 1 mm was taken out and tested as shownbelow.

As a result, the yellowness degree (N value) was 12 in a yellownessresistance test and the yellowness resistance was excellent. Thedispersibility of the sheet by observation with an eye was very good.

4-3: A Warmth-Keeping Effect by an Ethylene-Vinyl Acetate CopolymerResin (EVA)

When a resin warmth-keeping agent was added to EVA, the warmth-keepingeffect on the resin was explained.

Compounding and Molding

    ______________________________________                                        EVA (vinyl acetate content = 15%,                                                                  100    parts by weight                                   Ml = 1.5)                                                                     Ultraviolet absorbing agent                                                                        0.1    part by weight                                    Antioxidant          0.1    part by weight                                    Warmth-keeping agent 5      parts by weight                                   ______________________________________                                    

The above starting materials were kneaded with stirring by a Henschelmixer. The resulting kneaded mixture was fed to a biaxial extruder,pelletized at a processing temperature of 150° C., and inflation-moldedto obtain a film having a thickness of 100 μm and a width of 250 mm.Using this film, its warmth-keeping property was evaluated, and theresults are shown in Table 10.

                  TABLE 10                                                        ______________________________________                                        Warmth-keeping agent (sample No.)                                                                 12       13    H-8                                        Yellowness resistance test                                                                        12       13    21                                         Haze                8.5      8.9   8.5                                        Warmth-keeping property(ΔT)                                                                 1.5      2.0   0.9                                        ______________________________________                                    

As can be assumed from the transparency of the films of this inventionand infrared absorption spectrum charts of the warmth-keeping agents ofthe present invention, the warmth-keeping effects of the warmth-keepingagents of this invention are better than the conventional resinwarmth-keeping agent (H-8) as is clear from Table 10.

Application Example 5

The heat stabilizing effect of adding each of resin warmth-keepingagents composed of lithium aluminum complex type LAHCS anddawsonite-type NAHCS of the present invention (samples Nos. 6 to 11)obtained in Examples 5 to 10 to a chlorine-containing resin, theyellowness preventing effect and the dispersibility in the resin ofadding each of the above complex-type hydroxide carbonate salts to apolyolefin resin containing a halogen-remaining catalyst residue, andthe resin warmth-keeping effect of adding each of the above complex-typehydroxide carbonate salts to an ethylene/vinyl acetate copolymer resinwill be explained.

5-1: Evaluation by Addition of a Soft Vinyl Chloride Resin

To confirm the heat stabilizing effect on vinyl chloride resin by addingthe resin stabilizer, a soft vinyl chloride resin sheet was prepared bythe following compounding and molding method and evaluated.

Compounding

    ______________________________________                                        Vinyl chloride resin 100    parts by weight                                   (degree of polymerization:1050)                                               Dioctyl phthalate    50     parts by weight                                   Zinc laurate         0.4    part by weight                                    Dibenzoyl methane    0.1    part by weight                                    Dihydroxydiphenylpropane                                                                           0.2    part by weight                                    Samples (samples Nos. 6 and 7)                                                                     10     parts by weight                                   ______________________________________                                    

Molding Method

The above compounded composition was kneaded by a roll mill at atemperature of 150° C. for 7 minutes to prepare a uniform mixture havinga thickness of 0.5 mm. Then, the mixture was heated at 160° C. under apressure of 130 kg/□ for 5 minutes to prepare a soft vinyl chlorideresin sheet having a thickness of 1 mm, and its heat stabilizationeffect was evaluated.

As a result, the resin warmth-keeping agent showed a heat stabilizationduration time of 90 to 110 minutes until the sample showed a blackdecomposition. The warmth-keeping agent also showed a transparency(percent transmission %) of 89 to 90%. When the warmth-keeping agent wasadded to a soft vinyl chloride resin, it exhibited an excellent heatstabilizing effect and an excellent transparency-retaining effect.

5-2: Evaluation by a Polypropylene Resin

To confirm a yellowness preventing effect and a rust preventing effectof a polypropylene by the addition of a resin stabilizer, apolypropylene sheert was prepared by the following compounding andmolding procedures, and evaluated.

Compounding

    ______________________________________                                        Polypropylene resin containing                                                                     100    parts by weight                                   a halogen-remaining catalyst                                                  residue                                                                       Silton JC-30 (AB agent made by                                                                     0.05   part by weight                                    Mizusawa Industrial Chemicals                                                 Co., Ltd.)                                                                    Samples (samples Nos. 6 and 8)                                                                     0.3    part by weight                                    Bisphenol A          0.1    part by weight                                    ______________________________________                                    

Molding Method

The above compounded composition was pelletized at 260° C. by using anextruder. This sample pellet was placed in a stainless steel metal framehaving a thickness of 1 mm and a vertical length and a transverse lengthof 100 mm×100 mm and was overlapped and sandwiched between aphotographic thick ferro-type plate and a 2 mm-thick aluminum plate. Itwas then pressed at 230±3° C. for 30 minutes and then transfered to acooling press at 30±5° C. It was then cooled under a pressure of about50 kg/cm² per molding plane of projection. When the metal mold becamelower than 40° C., a polypropylene sheet having a thickness of 1 mm wastaken out, and tested in the following manner. As a result, it had anexcellent yellowness degree (N value) of 12 and 13 in the yellownessdegree test, and furthermore, the sheet had a very good dispersibilityby observation with eye.

5-3: Warmth-Keeping Effect on an Ethylene/Vinyl Acetate Copolymer Resin(EVA)

A warmth-keeping effect of adding each of the resin warmth-keepingagents (Examples 5 to 10) of this invention to EVA will be described.

Compounding and Molding

    ______________________________________                                        EVA (vinyl acetate content:                                                                       100    parts by weight                                    15%; MI = 1.5)                                                                Ultraviolet absorbing agent                                                                       0.1    part by weight                                     Antioxidant         0.1    part by weight                                     Warmth-keeping agent                                                                              10     parts by weight                                    ______________________________________                                    

The above starting materials were kneaded with stirring in a Henschelmixer. The resulting kneaded product was fed into a biaxial extruder andpelletized at a processing temperature of 150° C., and then the pelletwas inflation-molded to give a film having a width of 250 mm and athickness of 100 μm. The warmth-keeping property of the resulting filmwas evaluated, and the results are shown in Table 11.

                  TABLE 11                                                        ______________________________________                                        Type of the warmth-                                                           keeping agent                                                                 (sample No.)                                                                             6       7       8    9    10   11  H-7                             ______________________________________                                        Haze       10      10      7.5  7.7  7.5  7.5 17.7                            Warmth-keeping                                                                           1.7     1.7     2.1  1.9  2.0  1.8 1.4                             property (ΔT)                                                           ______________________________________                                    

EFFECT OF THE INVENTION

According to this invention, by using amorphous or pseudo-boehmite-typehydrated alumina as a starting aluminum component and aluminum metalcarbonate salt or bicarbonate salt, and maintaining the Al₂ O₃concentration in the reaction system in a high condition, it waspossible to synthesize the alkali aluminum complex hydroxide carbonatesalt. Furthermore, by using gibbsite as the starting aluminum, it waspossible to synthesize a lithium aluminum complex hydroxide carbonatesalt by a migration method.

By maintaining the concentration of the starting material in thereaction system high, the synthesis in a relatively short period of timebecomes possible, and the filtration and washing of the product can beextremely easy and an economically and industrially advatageousproduction method can be provided with good productivity and efficiency.

The lithium aluminum complex hydroxide carbonate salts (LAHCS) inaccordance with this invention are useful as compounding agents such asa stabilizer (halogen capturing agent), an anti-blocking agent, and awarmth-keeping agent (infrared absorbing agent) for thermoplasticresins, especially olefin resins.

Furthermore, dawsonite-type sodium aluminum complex hydroxide carbonatesalts (NAHCS) of this invention can be dispersed easily in resins, andhave a markedly reduced deterioration tendency, and are useful ascompounding agents for resins, especially as a warmth-keeping agent.Especially, NAHCS has excellent transparency in a condition which it iscompounded in a resin, shows a broad infrared ray spectrum absorptionand gives a resin film having excellent warmth-keeping property incomparison with hydrotalcite which is used as a conventional resinwarmth-keeping agent.

What is claimed is:
 1. A process for producing a lithium aluminumcomplex hydroxide carbonate salt, which comprises reacting amorphous orpseudo-boehmite hydrated alumina gel and a lithium carbonate orbicarbonate in an aqueous medium under such a condition that theconcentration of aluminum, calculated as alumina (Al₂ O₃), based on thetotal amount of the aqueous medium and the materials added to theaqueous medium, becomes 1 to 5% by weight, and the pH at the terminationof the reaction becomes 7 to 11,wherein the hydrated alumina is reactedwith the carbonate or the bicarbonate so that the amount of the carbonicacid ion is at least 0.25 mole based on the total aluminum atoms andwherein the reaction is carried out at a temperature of 50 to 90° C. 2.A process accord to claim 1 wherein the amorphous or pseudo-boehmitehydrated alumina gel is obtained by simultaneously mixing basic aluminumsulfate or aluminum sulfate and an alkali carbonate, said alkalicarbonate being present in an amount sufficient to form a hydrated gelwith the aluminum salt, forming the hydrated alumina gel, and separatingand washing the gel with water.
 3. A lithium aluminum complex hydroxidecarbonate salt according to claim 1 wherein when the lithium aluminumcomplex hydroxide carbonate salt is formed into an aqueous slurry havinga concentration of 5% by weight, the slurry of the carbonate salt has aspecific resistance of at least 8000 Ω·cm.
 4. A process for producing alithium aluminum complex hydroxide carbonate salt, which comprisesreacting a powder of gibbsite aluminum hydroxide with a lithium salt ofcarbonic acid, or a combination of a lithium compound and a carbonatesalt capable of forming a carbonic acid ion and a lithium ion in thepresence of water.
 5. A process according to claim 4 wherein thereaction is carried out at a temperature of at least 70° C. at a pH of 9to
 13. 6. A process according to claim 4 wherein the gibbsite aluminumhydroxide fine powders have an average particle diameter of 0.5 to 5 μm,and the fine powders are composed of 2% by weight or less of coarseparticles having a particle diameter of at least 20 μm.
 7. A processaccording to claim 4 wherein the concentration of the gibbsite aluminumhydroxide particles in the reaction system is maintained at a highconcentration of 10 to 20% by weight.
 8. A lithium aluminum complexhydroxide carbonate salt which has a composition represented by formula(6a)

    mAl.sub.2 O.sub.3.nM.sub.2 O.X.kH.sub.2 O                  (6a)

wherein X represents an inorganic anion composed mainly of a carbonicacid radical, M represents an alkali metal composed mainly of lithium, mis a number from 1.5 to 2.5, n is a number from 0.1 to 1, and k is anumber from 0 to 10,and which has an X-ray diffraction pattern shownbelow

    ______________________________________                                        Spacing d (A)                                                                 Index of a plane                                                                             Peak intensity                                                 ______________________________________                                        7.50 to 7.64   Large                                                          (002)                                                                         4.30 to 4.44   Small                                                          (110)                                                                         3.70 to 3.84   Large                                                          (004)                                                                         2.45 to 2.58   Medium                                                         (006)                                                                         2.20 to 2.30   Small                                                          (016)                                                                         1.85 to 2.08   Small                                                          (017)                                                                         1.40 to 1.52   Small                                                          (330)                                                                         1.38 to 1.48   Small                                                          (600)                                                                         ______________________________________                                    

the lamination asymmetry index (Is) being defined by

    Is=tan θ.sub.2 /tan θ.sub.1                    ( 7)

wherein θ₁ represents an angle formed between a peak perpendicular and apeak tangent on the narrow angle side at an X-ray diffraction peak of afixed spacing, and θ₂ represents an angle formed between the peakperpendicular and a peak tangent on the wide angle side at the peak, andthe Is being 1.0 or below at the peak of an index of a plane (016) and1.0 or below at the peak of an index of a plane (017).
 9. A lithiumaluminum complex hydroxide carbonate salt according to claim 8 whereinthe degree of orientation (OD) defined by formular (8)

    OD=I(002)/I(110)                                           (8)

wherein I (002) represents a relative intensity of a peak of X-raydiffraction (Cu-Kα) of the index of a plane (002) which appears at aspacing (d) of 7.67 to 7.84,is smaller than
 10. 10. A lithium aluminumcomplex hydroxide carbonate salt according to claim 8 wherein thecarbonate salt has a bulk density as measured in accordance with JISK6721 of 0.15 to 0.3.
 11. A lithium aluminum complex hydroxide carbonatesalt according to claim 8 wherein the carbonate salt has a particlediameter of 0.2 to 10 μm as measured by a laser scattering diffractionmethod.
 12. A compounding agent for resins which comprises the lithiumaluminum complex hydroxide carbonate salt according to claim
 8. 13. Awarmth-keeping agent or an infrared ray absorbing agent wherein saidagent comprises the lithium-aluminum complex hydroxide carbonate saltaccording to claim 8 and has a characteristic absorption spectrum in aninfrared absorption region which has absorptions at wavenumbers of 547,735, 1004 and 1375 cm⁻¹ with a wavenumber of 3443 cm⁻¹ as a mainabsorption.
 14. A halogen capturing agent composed of the lithiumaluminum complex hydroxide carbonate salt of claim 8.